These are representative sample records from Science.gov related to your search topic.
For comprehensive and current results, perform a real-time search at Science.gov.
1

Analysis of plutonium dioxide by coulometry  

SciTech Connect

Conditions for dissolution of plutonium dioxide have been determined. To transfer plutonium dioxides quantitatively in solution it should be heated with an HCl + HI mixture and boiled down three times in nitric acid. The disolution was monitored by potential scanning coulometry. The plutonium quantity was determined on a PKU-2 coulometric unit. Metrological parameters of the method have been evaluated.

Sklyarenko, I.S.; Andriets, V.V.; Chubukova, T.M.

1995-07-01

2

Water vapor adsorption on plutonium dioxide  

Microsoft Academic Search

Adsorption isotherms of water vapor on plutonium dioxide were measured ; gravimetrically at 30, 50, and 85 deg C. The data show water to be irreversibly ; chemisorbed until the oxide is saturated. Any subsequent adsorption is physical ; and completely reversible. The chemisorbed limit varied from 1 monolayer at 85 ; deg C to 3 monolayers at 30 deg

J. L. Stakebake; L. M. Steward

1973-01-01

3

Dissolution of plutonium dioxide in nitric acid  

SciTech Connect

Two alternative procedures of the electrochemical dissolution of plasmothermal plutonium dioxide in nitric acid were studied: reductive dissolution in the presence of U(IV) stabilized by hydrazine and dissolution in hot nitric acid at the alternating current supply. The current field accelerates dissolution of PuO{sub 2}.

Nikitina, G.P.; Zhukova, I.N.; Egorova, V.P. [Khlopin Radium Inst., St. Petersburg (Russian Federation)

1995-07-01

4

Supercritical fluid carbon dioxide cleaning of plutonium parts  

SciTech Connect

Supercritical fluid carbon dioxide is under investigation in this work for use as a cleaning solvent for the final cleaning of plutonium parts. These parts must be free of organic residue to avoid corrosion in the stockpile. Initial studies on stainless steel and full-scale mock-up parts indicate that the oils of interest are easily and adequately cleaned from the metal surfaces with supercritical fluid carbon dioxide. Results from compatibility studies show that undesirable oxidation or other surface reactions are not occurring during exposure of plutonium to the supercritical fluid. Cleaning studies indicate that the oils of interest are removed from the plutonium surface under relatively mild conditions. These studies indicate that supercritical fluid carbon dioxide is a very promising cleaning medium for this application.

Hale, S.J.

1991-12-31

5

PLUTONIUM UPTAKE BY PLANTS FROM SOIL CONTAINING PLUTONIUM-238 DIOXIDE PARTICLES  

EPA Science Inventory

Three plant species--alfalfa, lettuce, and radishes were grown in soils contaminated with plutonium-238 dioxide (238)PuO2 at concentrations of 23, 69, 92, and 342 nanocuries per gram (nCi/g). The length of exposure varied from 60 days for the lettuce and radishes to 358 days for ...

6

Emitted radiation characteristics of plutonium dioxide radioisotope thermoelectric generators  

NASA Technical Reports Server (NTRS)

The nuclear and emitted radiation characteristics of the radioisotope elements and impurities in commercial grade plutonium dioxide are presented in detail. The development of the methods of analysis are presented. Radioisotope thermoelectric generators (RTG) of 1575, 3468 and 5679 thermal watts are characterized with respect to neutron and gamma photon source strength as well as spatial and number flux distribution. The results are presented as a function of detector position and light element contamination concentration for fuel age ranging from 'fresh' to 18 years. The data may be used to obtain results for given O-18 and Pu-236 concentrations. The neutron and gamma photon flux and dose calculations compare favorably with reported experimental values for SNAP-27.

Gingo, P. J.; Steyn, J. J.

1971-01-01

7

Plutonium dioxide storage: Conditions for preparation and handling  

SciTech Connect

Desorption and adsorption of plutonium dioxide are derived from production-scale experiments that demonstrate techniques of preparing weapons-grade material for extended storage. In combination with data from literature, results define conditions for preparing and certifying PuO{sub 2} and provide essential information for developing and implementing a repackaging process compliant with DOE standards for safe storage of plutonium. As demonstrated by loss-on-ignition (LOI) analysis, adsorbates are effectively removed by heating the oxide in air at 950 C for two hours. After oxides are fired at this temperature, specific surface areas are consistently less than 5 m{sup 2}/g. Due to this low surface area, water adsorption by fired oxide is limited to a maximum of 0.2 mass % at 50% relative humidity. Kinetic data for the adsorption process show that water is accommodated on the oxide surface by a sequence of distinct first-order steps comprising five types of adsorbate interaction and accumulating ten molecular layers of H{sub 2}0 at 100% humidity. An equation defining the humidity dependence of the adsorption rate during the first step is applied in estimating time periods that a fired oxide may remain in given configurations without detrimental adsorption. Particle size measurements show that the source terms for environmental dispersal of oxides prepared by hydride-catalyzed reaction of metal and by oxalate calcination are approximately 20 and 0.1 mass %, respectively, and that the values are reduced by firing. Evidence for a chemical reaction between dioxide and water is discussed and practical applications of the results to oxide stabilization and LOI analysis are presented.

Haschke, J.M.; Ricketts, T.E.

1995-08-01

8

Dynamic shape factors for hydox-generated plutonium dioxide-type non-sperical objects  

E-print Network

The dynamic shape factors of HYDOX-generated plutonium dioxide-type non-spherical objects were estimated with computational methods. Leith's empirical methods were used to modify classical Stokes's law for aerosol dynamics (1987). The dynamic shape...

Lohaus, James Harold

2012-06-07

9

Criticality characteristics of mixtures of plutonium, silicon dioxide, Nevada tuff, and water  

SciTech Connect

The nuclear criticality characteristics of mixtures of plutonium, silicon dioxide, and water (Part A) or plutonium, silicon dioxide, Nevada Yucca Mountain tuff, and water (Part B) have become of interest because of the appearance of recent papers on the subject. These papers postulate that if excess weapons plutonium is vitrified into a silicate log and buried underground, a self-sustaining neutron chain reaction may develop given sufficient time and interaction with the burial medium. Moreover, given specific geologic actions resulting in postulated configurations, the referenced papers state that nuclear explosions could occur with multi-kiloton yields or yields equivalent to hundreds of tons of TNT.

Sanchez, R.; Myers, W.; Hayes, D. [and others

1997-01-01

10

Reactions of plutonium dioxide with water and oxygen-hydrogen mixtures: Mechanisms for corrosion of uranium and plutonium  

SciTech Connect

Investigation of the interactions of plutonium dioxide with water vapor and with an oxygen-hydrogen mixture show that the oxide is both chemically reactive and catalytically active. Correspondence of the chemical behavior with that for oxidation of uranium in moist air suggests that similar catalytic processes participate in the mechanism of moisture-enhanced corrosion of uranium and plutonium. Evaluation of chemical and kinetic data for corrosion of the metals leads to a comprehensive mechanism for corrosion in dry air, water vapor, and moist air. Results are applied in confirming that the corrosion rate of Pu in water vapor decreases sharply between 100 and 200 degrees C.

Haschke, John M.; Allen, Thomas H.; Morales, Luis A.

1999-06-18

11

Sonochemical Digestion of High-Fired Plutonium Dioxide Samples  

SciTech Connect

This work was performed as part of a broader effort to automate analytical methods for determining plutonium and other radioisotopes in environmental samples. The work described here represented a screening study to evaluate the effect of applying ultrasonic irradiation to dissolve high-fired plutonium oxide. The major findings of this work can be summarized as follows: (1) High-fired plutonium oxide does not undergo measurable dissolution when sonicated in nitric acid solutions, even at a high concentration range of nitric acid where the calculated thermodynamic solubility of plutonium oxide exceeds the ?g/mL level. (2) Applying organic complexants (nitrilotriacetic acid) and reductants (hydroxyurea) in 1.5 M nitric acid does not significantly increase the dissolution compared with digestion in nitric acid alone. Nearly all (99.5%) of the plutonium oxide remains undissolved under these conditions. (3) The action of a strong inorganic reductant, titanium trichloride in 25 wt% HCl, results in 40% dissolution of the plutonium oxide when the titanium trichloride concentration is ?1 wt% under sonication. (4) Oxidative treatment of plutonium oxide by freshly dissolved AgO ({approx}20 mg/mL) in 1.5 M nitric acid with sonication resulted in 95% plutonium oxide dissolution. However, the same treatment of plutonium oxide mechanically mixed with 50 mg of Columbia River sediment (CRS) results in a significant decrease of dissolution yield of plutonium oxide (<20% dissolved at the same AgO loading) because of parasitic consumption of AG(II) by oxidizable components of the CRS. (5) Digesting plutonium oxide in HF resulted in dissolution yields slightly higher than 80% for HF concentration from 6 M to 14 M. Sonication did not result in any improvement in dissolution efficiency in HF. (6) Mixed nitric acid/HF solutions result in a higher dissolution yield of plutonium oxide compared with digestion in HF alone (at the same HF concentrations). Practically quantitative dissolution of PuO2 can be achieved with 6 to 8 M nitric acid + 14 M HF or 8 M nitric acid + 4 M HF mixtures. In the latter case, quantitative dissolution of plutonium oxide was demonstrated only with sonication. Overall, the results indicate that applying ultrasound in an isolated cup horn configuration to dissolve refractory plutonium oxide does not offer any substantial advantage over conventional ?heat and mix? treatment. Oxidative treatment by AgO appears to be effective only when very little or no oxidizable materials are present in the digested sample. The catalytic use of Ag(II) in the ''Catalyzed Electrolytic Plutonium Oxide Dissolution'' technology would probably be more effective than using AgO because the Ag(II) is continually regenerated electrochemically. Reductive treatment with titanium trichloride in HCl solution proves to be less efficient than the previously observed effect based on in situ generation of Ti(III) in phosphoric acid and sulfuric acid media using a dip probe sonication setup. The previous experiments, however, were performed at higher temperature and with non-steady concentration profiles of Ti(III) ion in the process of sonochemical digestion.

Sinkov, Sergei I.; Lumetta, Gregg J.

2006-10-12

12

Toxicity of inhaled plutonium dioxide in beagle dogs  

SciTech Connect

This study was conducted to determine the biological effects of inhaled {sup 238}PuO{sub 2} over the life spans of 144 beagle dogs. The dogs inhaled one of two sizes of monodisperse aerosols of {sup 238}PuO{sub 2} to achieve graded levels of initial lung burden (ILB). The aerosols also contained {sup 169}Yb to provide a {gamma}-ray-emitting label for the {sup 238}Pu inhaled by each dog. Excreta were collected periodically over each dog`s life span to estimate plutonium excretion; at death, the tissues were analyzed radiochemically for plutonium activity. The tissue content and the amount of plutonium excreted were used to estimate the ILB. These data for each dog were used in a dosimetry model to estimate the ILB. These data for each dog were used in a dosimetry model to estimate tissue doses. The lung, skeleton and liver received the highest {alpha}-particle doses, ranging from 0.16-68 Gy for the liver. At death, all dogs were necropsied, and all organs and lesions were sampled and examined by histopathology. Findings of non-neoplastic changes included neutropenia and lymphopenia that developed in a dose-related fashion soon after inhalation exposure. These effects persisted for up to 5 years in some animals, but no other health effects could be related to the blood changes observed. Radiation pneumonitis was observed among the dogs with the highest ILBs. Deaths from radiation pneumonitis occurred from 1.5 to 5.4 years after exposure. Tumors of the lung, skeleton and liver occurred beginning at about 3 years after exposure. These findings in dogs suggest that similar dose-related biological effects could be expected in humans accidentally exposed to {sup 238}PuO{sub 2}. 89 refs., 10 figs., 11 tab.

Muggenburg, M.A.; Guilmette, R.A.; Mewhinney, J.A. [Lovelace Biomedical and Environmental Research Inst., Albuquerque, NM (United States)] [and others

1996-03-01

13

Dissolution of plutonium dioxide using HCl-HF  

SciTech Connect

High-fired PuO/sub 2/ (950/sup 0/ to 1700/sup 0/C) can be dissolved in boiling 6.1 M HCl when the fluoride ion concentration to plutonium mole (F/sup -//Pu) ratio is >0.5. The amount of PuO/sub 2/ (950/sup 0/C calcined oxide) dissolved in 1 hour increased from approx.0.2% to 66%, 91%, and 100% as the F/sup -//Pu ratio increased from 0 to 0.5, 1.0, and 1.8, respectively. The PuO/sub 2/ dissolution rates in HCl-CaF/sub 2/ solutions decrease with increasing oxide calcination temperatures and decreasing oxide surface areas. At a F/sup -//Pu ratio of 1.8, the 1700/sup 0/C calcined oxide was completely dissolved in 2.5 hours versus 1 hour for the 950/sup 0/C calcined oxide.

Bray, L.A.; Ryan, J.L.; Wheelwright, E.J.

1986-10-01

14

Recovery of plutonium from plutonium-beryllium neutron sources.  

National Technical Information Service (NTIS)

At the Los Alamos National Laboratory, plutonium-beryllium neutron sources have traditionally been processed for plutonium recovery by precipitating the plutonium as plutonium oxalate, calcining to plutonium dioxide, redissolving the oxide and then precip...

M. J. Palmer

1990-01-01

15

The effect of plutonium dioxide water surface coverage on the generation of hydrogen and oxygen  

SciTech Connect

The conditions for the production of oxygen during radiolysis of water adsorbed onto plutonium dioxide powder are discussed. Studies in the literature investigating the radiolysis of water show that both oxygen and hydrogen can be generated from water adsorbed on high-purity plutonium dioxide powder. These studies indicate that there is a threshold in the amount of water below which oxygen is not generated. The threshold is associated with the number of monolayers of adsorbed water and is shown to occur at approximately two monolayers of molecularly adsorbed water. Material in equilibrium with 50% relative humidity (RH) will be at the threshold for oxygen generation. Using two monolayers of molecularly adsorbed water as the threshold for oxygen production, the total pressure under various conditions is calculated assuming stoichiometric production of hydrogen and oxygen. The specific surface area of the oxide has a strong effect on the final partial pressure. The specific surface areas resulting in the highest pressures within a 3013 container are evaluated. The potential for oxygen generation is mitigated by reduced relative humidity, and hence moisture adsorption, at the oxide surface which occurs if the oxide is warmer than the ambient air. The potential for oxygen generation approaches zero as the temperature difference between the ambient air and the material approaches 6 C.

Veirs, Douglas K. [Los Alamos National Laboratory; Berg, John M. [Los Alamos National Laboratory; Crowder, Mark L. [Savannah River National Laboratory

2012-06-20

16

Production and characterization of plutonium dioxide particles as a quality control material for safeguards purposes.  

PubMed

Plutonium (Pu) dioxide particles were produced from certified reference material (CRM) 136 solution (CRM 136-plutonium isotopic standard, New Brunswick Laboratory, Argonne, IL, U.S.A., 1987) using an atomizer system on December 3, 2009 after chemical separation of americium (Am) on October 27, 2009. The highest density of the size distribution of the particles obtained from 312 particles on a selected impactor stage was in the range of 0.7-0.8 ?m. The flattening degree of 312 particles was also estimated. The isotopic composition of Pu and uranium (U) and the amount of Am were estimated by thermal ionization mass spectrometry (TIMS), inductively coupled plasma mass spectrometry (ICPMS), and ?-spectrometry. Within uncertainties the isotopic composition of the produced particles is in agreement with the expected values, which were derived from the decay correction of the Pu isotopes in the CRM 136. The elemental ratio of Am to Pu in the produced particles was determined on the 317th and 674th day after Am separation, and the residual amount of Am in the solution was estimated. The analytical results of single particles by micro-Raman-scanning electron microscopy (SEM)-energy-dispersive X-ray spectrometry (EDX) indicate that the produced particles are Pu dioxide. Our initial attempts to measure the density of two single particles gave results with a spread value accompanied by a large uncertainty. PMID:22372509

Shinonaga, Taeko; Donohue, David; Aigner, Helmut; Bürger, Stefan; Klose, Dilani; Kärkelä, Teemu; Zilliacus, Riitta; Auvinen, Ari; Marie, Olivier; Pointurier, Fabien

2012-03-20

17

Ground-state properties and high-pressure behavior of plutonium dioxide: Density functional theory calculations  

NASA Astrophysics Data System (ADS)

Plutonium dioxide is of high technological importance in nuclear fuel cycle and is particularly crucial in long-term storage of Pu-based radioactive waste. Using first-principles density-functional theory, in this paper we systematically study the structural, electronic, mechanical, thermodynamic properties, and pressure-induced structural transition of PuO2 . To properly describe the strong correlation in Pu5f electrons, the local-density approximation (LDA)+U and the generalized gradient approximation+U theoretical formalisms have been employed. We optimize U parameter in calculating the total energy, lattice parameters, and bulk modulus at nonmagnetic, ferromagnetic, and antiferromagnetic configurations for both ground-state fluorite structure and high-pressure cotunnite structure. Best agreement with experiments is obtained by tuning the effective Hubbard parameter U at around 4 eV within LDA+U approach. After carefully testing the validity of the ground-state calculation, we further investigate the bonding nature, elastic constants, various moduli, Debye temperature, hardness, ideal tensile strength, and phonon dispersion for fluorite PuO2 . Some thermodynamic properties, e.g., Gibbs free energy, volume thermal expansion, and specific heat are also calculated. As for cotunnite phase, besides elastic constants, various moduli, and Debye temperature at 0 GPa, we have further presented our calculated electronic, structural, and magnetic properties for PuO2 under pressure up to 280 GPa. A metallic transition at around 133 GPa and an isostructural transition in pressure range of 75-133 GPa are predicted. Additionally, as an illustration on the valency trend and subsequent effect on the mechanical properties, the calculated results for other actinide metal dioxides ( ThO2 , UO2 , and NpO2 ) are also presented.

Zhang, Ping; Wang, Bao-Tian; Zhao, Xian-Geng

2010-10-01

18

THE PREPARATION OF PLUTONIUM-ALUMINUM AND OTHER PLUTONIUM ALLOYS  

Microsoft Academic Search

The preparation of plutonium-aluminum alloys by the direct reduction of plutonium trifluoride and plutonium dioxide is described. Plutonium trifluoride is reduced more rapidly at 800 deg C than at 1125 deg C with liquid aluminum owing to the evolution of gaseous aluminum monofluoride at the lower temperature. Plutonium dioxide is reduced readily by an excess of liquid aluminum at 1200

Runnalls; O. J. C

1958-01-01

19

Two convenient low-temperature routes to single crystals of plutonium dioxide  

NASA Astrophysics Data System (ADS)

During the solvothermal synthesis of a low-dimensional borate, KB5O7(OH)2?2H2O, in the presence of Pu(III), single crystals of plutonium dioxide unexpectedly formed. Single crystals of PuO2 also formed during the hydrothermal synthesis of another borate, Na2B5O8(OH)?2H2O, in the presence of Pu(III). The reactions were conducted at 170 °C and 150 °C, respectively, which are much lower temperature than previously reported preparations of crystalline PuO2. Yellow-green crystals with a tablet habit were characterized by single crystal X-ray diffraction and solid-state UV-vis-NIR absorption spectroscopy. The crystal structure was solved by direct methods with R1 = 1.26% for 19 unique observed reflections. PuO2 is cubic, space group Fm3?m, and adopts the fluorite structure type. The lattice parameter was determined to be a = 5.421(5) Å giving a volume of 159.3(2) Å3. The absorption spectrum is consistent with Pu(IV).

Meredith, Nathan A.; Wang, Shuao; Diwu, Juan; Albrecht-Schmitt, Thomas E.

2014-11-01

20

Assessment of the risk of transporting plutonium dioxide by cargo aircraft  

Microsoft Academic Search

To enable easy comparison, all the plutonium shipping evaluations have used the same bases. In each, the results have been related to a future time--the early 1980s--when plutonium shipments are expected to be more frequent. The characteristics of the nuclear economy used in this analysis are: A total of 18 metric tons (MT) of plutonium is shipped annually, via the

T. I. McSweeney; J. F. Johnson

1977-01-01

21

Interactions of Plutonium Dioxide with Water and Oxygen-Hydrogen Mixtures  

SciTech Connect

Pressure-volume-temperature data and mass spectrometric results obtained during exposure of PuO{sub 2} to D{sub 2}O show that the dioxide reacts with water at room temperature to produce a higher oxide (PuO{sub 2+x})and H{sub 2}. Results demonstrate that PuO{sub 2+x} is the thermodynamically stable oxide in air. The absence of O{sub 2} at detectable levels in the gas phase implies that radiolytic decomposition of water to the elements is not a significant reaction. The rate of the PuO{sub 2}+H{sub 2}O reaction is 6{+-}4 nmol H{sub 2}/m{sup 2} day, a value that is independent of the H{sub 2}O concentration on the oxide over a range that extends from fractional monolayer coverage to saturation by liquid water. Evaluation of literature data shows that oxide compositions in excess of PuO{sub 2.25} are attained, but the maximum value of x is unknown. During exposure of PuO{sub 2} to a 2:1 D{sub 2}:O{sub 2} mixture at room temperature, the elements combine by a process consistent with a surface-catalyzed reaction. Water is simultaneously formed by the H{sub 2}+O{sub 2} reaction and consumed by the PuO{sub 2} + H{sub 2}O reaction and accumulates until the opposing rates are equal. Thereafter, PuO{sub 2+x} is formed at a constant rate by the water-catalyzed PuO{sub 2} + O{sub 2} reaction. The failure of earlier attempts to prepare higher oxides of plutonium is discussed and the catalytic cycle that promotes the reaction of PuO{sub 2} with O{sub 2} is described. Implications of the results for extended storage and environmental chemistry of oxide are examined. Moisture-catalyzed oxidation of PuO{sub 2} accounts for observation of both pressure increases and decreases in oxide storage containers with air atmospheres. Application of the experimental rate results indicates that the reaction of a typical oxide with 0.5 mass % of adsorbed water maybe complete after 25 to 50 years at room temperature.

Haschke, J.M.; Allen, T.H.

1999-01-01

22

A kinetic study of plutonium dioxide dissolution in hydrochloric acid using iron (II) as an electron transfer catalyst  

SciTech Connect

Effective dissolution of plutonium dioxide has traditionally been accomplished by contact with strong nitric acid containing a small amount of fluoride at temperatures of {approximately} 100 C. In spite of these aggressive conditions, PuO{sub 2} dissolution is sometimes incomplete requiring additional contact with the solvent. This work focused on an alternative to conventional dissolution in nitric acid where an electron transfer catalyst, Fe(II), was used in hydrochloric acid. Cyclic voltammetry was employed as an in-situ analytical technique for monitoring the dissolution reaction rate. The plutonium oxide selected for this study was decomposed plutonium oxalate with > 95% of the material having a particle diameter (< 70 {micro}m) as determined by a scanning laser microscopy technique. Attempts to dry sieve the oxide into narrow size fractions prior to dissolution in the HCl-Fe(II) solvent system failed, apparently due to significant interparticle attractive forces. Although sieve splits were obtained, subsequent scanning laser microscopy analysis of the sieve fractions indicated that particle segregation was not accomplished and the individual sieve fractions retained a particle size distribution very similar to the original powder assemblage. This phenomena was confirmed through subsequent dissolution experiments on the various screen fractions which illustrated no difference in kinetic behavior between the original oxide assemblage and the sieve fractions.

Fife, K.W.

1996-09-01

23

Recovery of plutonium from plutonium-beryllium neutron sources  

Microsoft Academic Search

At the Los Alamos National Laboratory, plutonium-beryllium neutron sources have traditionally been processed for plutonium recovery by precipitating the plutonium as plutonium oxalate, calcining to plutonium dioxide, redissolving the oxide and then precipitating as oxalate again. In most cases three dissolutions of the oxide are required to reduce beryllium content enough to meet specifications. We first introduced an ion-exchange process

1990-01-01

24

Criticality characteristics of mixtures of plutonium, silicon dioxide, Nevada tuff, and water  

SciTech Connect

The major objective of this study has been to examine the possibility of a nuclear explosion (and evaluate this event if it is possible) should 50 to 100 kg of plutonium be mixed with SiO{sub 2}, vitrified, placed within a heavy steel container, and buried in the material known as Nevada tuff. To accomplish this objective we have created a survey of the critical states or configurations of mixtures of plutonium, SiO{sub 2}, tuff, and water and examined these data to isolate those configurations that might be unstable or autocatalytic. The survey of critical data now exists and is published herein. We identify regions of criticality instability with the possibility of autocatalytic power behavior (the existence of such autocatalytic phenomena is not new). Autocatalytic power behavior is possible for a very limited range of wet systems, but this behavior is improbable. A quantitative and conservative evaluation of the fission power behavior of these autocatalytic mixtures shows that no explosion should be expected.

Sanchez, R.; Myers, W.; Hayes, D.; Kimpland, R. [and others

1996-09-01

25

Criticality characteristics of mixtures of plutonium, silicon dioxide, Nevada tuff, and water  

SciTech Connect

The parameters that determine when critical mixtures of {sup 239}Pu, SiO{sub 2}, and water and mixtures of {sup 239}Pu, Nevada tuff, and water are capable of sustaining an increasing neutron chain reaction as may be caused by a positive void coefficient at constant temperature are established. A single canister is considered that is loaded with up to 75 kg of {sup 239}Pu. A survey of critical spherical mixtures of plutonium, SiO{sub 2}, tuff, and water at constant temperature is created and these results are examined to determine the mixtures that might be autocatalytic. Regions of criticality instability are identified that have the possibility of autocatalytic power behavior. A positive void coefficient is possible for a very limited range of wet systems.

Sanchez, R.; Myers, W.; Hayes, D.; Kimpland, R.; Jaegers, P.; Paternoster, R.; Rojas, S.; Anderson, R.; Stratton, W. [Los Alamos National Lab., NM (United States)

1998-06-01

26

Kinetics of Reaction Between Plutonium Dioxide and Water at 25 C to 350 C: Formation and Properties of the PuO{sub 2+X} Phase  

SciTech Connect

Results of microbalance, pressure-volume-temperature, and mass spectrometric measurements show that a higher oxide of plutonium, PuO{sub 2+x}, and hydrogen are formed by reaction of plutonium dioxide with water at 25 C to 350 C. PuO{sub 2+x} has an intense green color consistent with the presence of Pu(VI). An oxide composition in excess of PuO{sub 2.25} is identified, but the maximum value of x is undefined. Reaction rates derived from linear mass-time and pressure-time data are described by an Arrhenius relationship that yields an activation energy of 9.4 {+-} 0.6 kcal/mol for the PuO{sub 2} + H{sub 2}O reaction. X-ray diffraction data for PuO{sub 2+x} shows that the oxide has a fluorite-related structure consistent with substitution of Pu(VI) on cationic lattice sites and accommodation of additional oxygen on interstitial sites. The cubic lattice parameter has a low, but well-defined, linear dependence on the O:Pu ratio, suggesting that PuO{sub 2+x} forms as a continuous solid solution. The failure of earlier attempts to prepare higher oxides of plutonium is attributed to slow oxidation kinetics and insensitivity of diagnostic techniques. Similarities of the PuO{sub 2+x} and UO{sub 2+x} phase are examined and relevance of the results to plutonium technology and environmental issues is discussed.

Luis A. Morales; John M. Haschke; Thomas H. Allen

1999-05-01

27

Plutonium controversy  

SciTech Connect

The toxicity of plutonium is discussed, particularly in relation to controversies surrounding the setting of radiation protection standards. The sources, amounts of, and exposure pathways of plutonium are given and the public risk estimated. (ACR)

Richmond, C.R.

1980-01-01

28

Alternative technical summary report for direct disposition in deep boreholes: Direct disposal of plutonium metal/plutonium dioxide in compound canisters, Version 4.0. Fissile Materials Disposition Program  

SciTech Connect

This report summarizes and compares the Immobilized and Direct Beep Borehole Disposition Alternatives. The important design concepts, facility features and operational procedures are briefly described, and a discussion of the issues that affect the evaluation of each alternative against the programmatic assessment criteria that have been established for selecting the preferred alternatives for plutonium disposition.

Wijesinghe, A.M.

1996-08-23

29

Plutonium pyrophoricity  

Microsoft Academic Search

A review of the published literature on ignition and burning of plutonium metal was conducted in order to better define the characteristic of pyrophoric plutonium. The major parameter affecting ignition is the surface area\\/mass ratio of the sample. Based on this parameter, plutonium metal can be classified into four categories: (1) bulk metal, (2) film and foils, (3) chips and

Stakebake

1992-01-01

30

Plutonium aging  

SciTech Connect

The author describes the plutonium aging program at the Los Alamos National Laboratory. The aging of plutonium components in the US nuclear weapons stockpile has become a concern due to several events: the end of the cold war, the cessation of full scale underground nuclear testing as a result of the Comprehensive Test Ban Treaty (CTBT) and the closure of the Rocky Flats Plant--the site where the plutonium components were manufactured. As a result, service lifetimes for nuclear weapons have been lengthened. Dr. Olivas will present a brief primer on the metallurgy of plutonium, and will then describe the technical approach to ascertaining the long-term changes that may be attributable to self-radiation damage. Facilities and experimental techniques which are in use to study aging will be described. Some preliminary results will also be presented.

Olivas, J.D.

1999-03-01

31

Fissile Material Disposition Program: Deep Borehole Disposal Facility PEIS data input report for direct disposal. Direct disposal of plutonium metal/plutonium dioxide in compound metal canisters. Version 3.0  

SciTech Connect

The US Department of Energy (DOE) is examining options for disposing of excess weapons-usable nuclear materials [principally plutonium (Pu) and highly enriched uranium (HEU)] in a form or condition that is substantially and inherently more difficult to recover and reuse in weapons production. This report is the data input report for the Programmatic Environmental Impact Statement (PEIS). The PEIS examines the environmental, safety, and health impacts of implementing each disposition alternative on land use, facility operations, and site infrastructure; air quality and noise; water, geology, and soils; biotic, cultural, and paleontological resources; socioeconomics; human health; normal operations and facility accidents; waste management; and transportation. This data report is prepared to assist in estimating the environmental effects associated with the construction and operation of a Deep Borehole Disposal Facility, an alternative currently included in the PEIS. The facility projects under consideration are, not site specific. This report therefore concentrates on environmental, safety, and health impacts at a generic site appropriate for siting a Deep Borehole Disposal Facility.

Wijesinghe, A.M.; Shaffer, R.J.

1996-01-15

32

Plutonium pyrophoricity  

SciTech Connect

A review of the published literature on ignition and burning of plutonium metal was conducted in order to better define the characteristic of pyrophoric plutonium. The major parameter affecting ignition is the surface area/mass ratio of the sample. Based on this parameter, plutonium metal can be classified into four categories: (1) bulk metal, (2) film and foils, (3) chips and turnings, and (4) powder. Other parameters that can alter the ignition of the metal include experimental, chemical, physical, and environmental effects. These effects are reviewed in this report. It was concluded from this review that pyrophoric plutonium can be conservatively defined as: Plutonium metal that will ignite spontaneously in air at a temperature of 150{degrees}C or below in the absence of external heat, shock, or friction. The 150{degrees}C temperature was used to compensate for the self-heating of plutonium metal. For a practical definition of whether any given metal is pyrophoric, all of the factors affecting ignition must be considered.

Stakebake, J.L.

1992-06-02

33

Evaluation of the surface properties of calcined plutonium peroxide  

Microsoft Academic Search

Seven batches of calcined plutonium peroxide were prepared and characterized by nitrogen and argon adsorption. The surface areas of all batches were similar and unaffected by grinding, indicating most of the exposed area was internal. Water vapor adsorbed on the plutonium dioxide was found to decrease nitrogen adsorption at -196°C and thereby reduce the BET surface area. Porosity analysis by

J. L. Stakebake; H. N. Robinson

1984-01-01

34

Dynamic characteristics of mixtures of plutonium, Nevada tuff, and water  

SciTech Connect

One of the technical options being considered for long term disposition of weapons grade plutonium is geologic storage at Yucca Mountain. Multikilogram quantities of plutonium are to be vitrified, placed within a heavy steel container, and buried in the material know as Nevada tuff. It has been postulated that after ten thousand years, geologic and chemical processes would have disintegrated the steel container and created the possibility for plutonium to form mixtures with Nevada tuff and water that could lead to a nuclear explosion in the range of kilotons. A survey and description of critical homogeneous mixtures of plutonium, silicon dioxide, Nevada tuff, and water which also identified the mixture regimes where autocatalytic dynamic behavior is possible was completed. This study is a follow up of this survey and the major objective is to examine the dynamic behavior of the worst case critical and supercritical configurations of plutonium, water and Nevada tuff.

Myers, W.; Rojas, S.; Kimpland, R.H.; Jaegers, P.J.; Sanchez, R.G.; Hayes, D.; Paternoster, R.; Anderson, R.; Stratton, W.

1996-02-01

35

PLUTONIUM-239 AND AMERICIUM-241 UPTAKE BY PLANTS FROM SOIL  

EPA Science Inventory

Alfalfa was grown in soil contaminated with plutonium-239 dioxide (239PuO2) at a concentration of 29.7 nanocuries per gram (nCi/g). In addition to alfalfa, radishes, wheat, rye, and tomatoes were grown in soils contaminated with americium-241 nitrate (241Am(NO3)3) at a concentrat...

36

Comparison of Spectroscopic Data with Cluster Calculations of Plutonium, Plutonium Dioxide and Uranium Dioxide  

SciTech Connect

Using spectroscopic data produced in the experimental investigations of bulk systems, including X-Ray Absorption Spectroscopy (XAS), Photoelectron Spectroscopy (PES) and Bremstrahlung Isochromat Spectroscopy (BIS), the theoretical results within for UO{sub 2}{sup 6}, PuO{sub 2}{sup 6} and Pu{sup 7} clusters have been evaluated. The calculations of the electronic structure of the clusters have been performed within the framework of the Relativistic Discrete-Variational Method (RDV). The comparisons between the LLNL experimental data and the Russian calculations are quite favorable. The cluster calculations may represent a new and useful avenue to address unresolved questions within the field of actinide electron structure, particularly that of Pu. Observation of the changes in the Pu electronic structure as a function of size suggests interesting implications for bulk Pu electronic structure.

Tobin, J G; Yu, S W; Chung, B W; Ryzhkov, M V; Mirmelstein, A

2012-05-15

37

MOLTEN PLUTONIUM PUMP EXPERIMENT  

Microsoft Academic Search

The Molten Plutonium Pump Experiment was a subcritical mock-up of a ; reactor core in which a plutonium-iron alloy was circulated by means of a sodium ; lift pump. Sodium for the lift pumping was circulated by an E. M. pump in an ; isothermal loop at 500 deg C. The purpose of the test was to study pump ;

J. E. Deverall; G. L. Caldwell

1962-01-01

38

31. VIEW OF A WORKER HOLDING A PLUTONIUM 'BUTTON.' PLUTONIUM, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

31. VIEW OF A WORKER HOLDING A PLUTONIUM 'BUTTON.' PLUTONIUM, A MAN-MADE SUBSTANCE, WAS RARE. SCRAPS RESULTING FROM PRODUCTION AND PLUTONIUM RECOVERED FROM RETIRED NUCLEAR WEAPONS WERE REPROCESSED INTO VALUABLE PURE-PLUTONIUM METAL (9/19/73). - Rocky Flats Plant, Bounded by Indiana Street & Routes 93, 128 & 72, Golden, Jefferson County, CO

39

Effects of water vapor on the surface chemistry of calcined plutonium peroxide as determined by nitrogen adsorption  

Microsoft Academic Search

The amount of water vapor readsorbed on plutonium dioxide, following calcination of plutonium peroxide at 400°C, was measured for 14 oxide samples. It was determined that this adsorbed water decreased nitrogen adsorption and thus the specific surface area of the oxide, as determined by the method derived by Brunauer, Emmett, and Teller (BET) was also reduced. As water was desorbed

J. L. Stakebake; H. H. Robinson

1983-01-01

40

Plutonium storage phenomenology  

SciTech Connect

Plutonium has been produced, handled, and stored at Department of Energy (DOE) facilities since the 1940s. Many changes have occurred during the last 40 years in the sources, production demands, and end uses of plutonium. These have resulted in corresponding changes in the isotopic composition as well as the chemical and physical forms of the processed and stored plutonium. Thousands of ordinary food pack tin cans have been used successfully for many years to handle and store plutonium. Other containers have been used with equal success. This paper addressees the exceptions to this satisfactory experience. To aid in understanding the challenges of handling plutonium for storage or immobilization the lessons learned from past storage experience and the necessary countermeasures to improve storage performance are discussed.

Szempruch, R.

1995-12-01

41

Plutonium radiation surrogate  

DOEpatents

A self-contained source of gamma-ray and neutron radiation suitable for use as a radiation surrogate for weapons-grade plutonium is described. The source generates a radiation spectrum similar to that of weapons-grade plutonium at 5% energy resolution between 59 and 2614 keV, but contains no special nuclear material and emits little .alpha.-particle radiation. The weapons-grade plutonium radiation surrogate also emits neutrons having fluxes commensurate with the gamma-radiation intensities employed.

Frank, Michael I. (Dublin, CA)

2010-02-02

42

Evaluation of the surface properties of calcined plutonium peroxide  

SciTech Connect

Seven batches of calcined plutonium peroxide were prepared and characterized by nitrogen and argon adsorption. The surface areas of all batches were similar and unaffected by grinding, indicating most of the exposed area was internal. Water vapor adsorbed on the plutonium dioxide was found to decrease nitrogen adsorption at -196/sup 0/C and thereby reduce the BET surface area. Porosity analysis by both the t and ..cap alpha../sub s/ methods showed the oxide contained mesopores and possibly macropores, but no micropores. Pore structures of the samples were evaluated by the modelless method where the average hydraulic core diameter was 22 A.

Stakebake, J.L.; Robinson, H.N.

1984-02-24

43

Synthesis of Diphosphine Dioxides for Extraction of Actinides using Supported Liquid Membranes Technology  

Microsoft Academic Search

A recurrent method for synthesis of linear and macrocyclic diphosphine dioxides has been applied to synthesize new phosphoryl ligands with P-C bonds, stable in strongly acidic aqueous solution and therefore useful for extraction and recovering of actinides from nuclear wastes. The influence of the structural parameters on their liquid-liquid extraction properties of plutonium and neptunium is studied. Plutonium and Neptunium

Henri-Jean Cristau; Patrick Mouchet; Jean-François Dozol; Helene Rouquette

1996-01-01

44

Plutonium dissolution process  

SciTech Connect

A two-step process is described for dissolving plutonium metal, which two steps can be carried out sequentially or simultaneously. Plutonium metal is exposed to a first mixture containing approximately 1.0M--1.67M sulfamic acid and 0.0025M--0.1M fluoride, the mixture having been heated to a temperature between 45 C and 70 C. The mixture will dissolve a first portion of the plutonium metal but leave a portion of the plutonium in an oxide residue. Then, a mineral acid and additional fluoride are added to dissolve the residue. Alteratively, nitric acid in a concentration between approximately 0.05M and 0.067M is added to the first mixture to dissolve the residue as it is produced. Hydrogen released during the dissolution process is diluted with nitrogen. 2 figs.

Vest, M.A.; Fink, S.D.; Karraker, D.G.; Moore, E.N.; Holcomb, H.P.

1996-01-09

45

Plutonium dissolution process  

DOEpatents

A two-step process for dissolving plutonium metal, which two steps can be carried out sequentially or simultaneously. Plutonium metal is exposed to a first mixture containing approximately 1.0M-1.67M sulfamic acid and 0.0025M-0.1M fluoride, the mixture having been heated to a temperature between 45.degree. C. and 70.degree. C. The mixture will dissolve a first portion of the plutonium metal but leave a portion of the plutonium in an oxide residue. Then, a mineral acid and additional fluoride are added to dissolve the residue. Alteratively, nitric acid in a concentration between approximately 0.05M and 0.067M is added to the first mixture to dissolve the residue as it is produced. Hydrogen released during the dissolution process is diluted with nitrogen.

Vest, Michael A. (Oak Park, IL); Fink, Samuel D. (Aiken, SC); Karraker, David G. (Aiken, SC); Moore, Edwin N. (Aiken, SC); Holcomb, H. Perry (North Augusta, SC)

1996-01-01

46

Plutonium: The disposal decision  

Microsoft Academic Search

Energy`s dual-track disposition strategy was driven by three principal assumptions: (1) Surplus plutonium should not be left indefinitely in storage because it is too easy to reuse it in weapons (the {open_quotes}breakout{close_quotes} scenario) and too vulnerable to theft, particularly in Russia where inventory controls are weak. (2) Given the fact that the world is already awash in civil plutonium (upwards

1997-01-01

47

Dynamics of pluotinum dioxide  

NASA Astrophysics Data System (ADS)

We report lattice and molecular dynamics studies on the vibrational and thermodynamic properties of PuO2. We have used a transferable interatomic model to understand the properties of the compound. Our computed elastic data, structure and specific heat are in good agreement with reported experimental and first principles results. We observe that plutonium dioxide exhibits fast ion conduction at around 2500 K. The mean square displacements of the oxygen atoms are an order of magnitude greater than that of Pu. The greater amplitude and smaller size of the oxygen ion facilitates its easy diffusion. This behavior is in sync with similar fast ion conduction in other nuclear oxides like UO2 and ThO2.

Goel, Prabhatasree; Mittal, R.; Chaplot, S. L.

2012-06-01

48

Plutonium Disposition Now!  

SciTech Connect

A means for use of existing processing facilities and reactors for plutonium disposition is described which requires a minimum capital investment and allows rapid implementation. The scenario includes interim storage and processing under IAEA control, and fabrication into MOX fuel in existing or planned facilities in Europe for use in operating reactors in the two home countries. Conceptual studies indicate that existing Westinghouse four-loop designs can safety dispose of 0.94 MT of plutonium per calendar year. Thus, it would be possible to consume the expected US excess stockpile of about 50 MT in two to three units of this type, and it is highly likely that a comparable amount of the FSU excess plutonium could be deposed of in a few VVER-1000`s. The only major capital project for this mode of plutonium disposition would be the weapons-grade plutonium processing which could be done in a dedicated international facility or using existing facilities in the US and FSU under IAEA control. This option offers the potential for quick implementation at a very low cost to the governments of the two countries.

Buckner, M.R.

1995-05-24

49

Plutonium waste incineration using pyrohydrolysis  

Microsoft Academic Search

Waste generated by Savannah River Site (SRS) plutonium operations includes a contaminated organic waste stream. A conventional method for disposing of the organic waste stream and recovering the nuclear material is by incineration. When the organic material is burned, the plutonium remains in the incinerator ash. Plutonium recovery from incinerator ash is highly dependent on the maximum temperature to which

1991-01-01

50

Plutonium: An introduction  

SciTech Connect

This report is a summary of the history and properties of plutonium. It presents information on the atoms, comparing chemical and nuclear properties. It looks at the history of the atom, including its discovery and production methods. It summarizes the metallurgy and chemistry of the element. It also describes means of detecting and measuring the presence and quantity of the element.

Condit, R.H.

1993-10-01

51

Atomic spectrum of plutonium  

SciTech Connect

This report contains plutonium wavelengths, energy level classifications, and other spectroscopic data accumulated over the past twenty years at Laboratoire Aime Cotton (LAC) Argonne National Laboratory (ANL), and Lawrence Livermore National Laboratory (LLNL). The primary purpose was term analysis: deriving the energy levels in terms of quantum numbers and electron configurations, and evaluating the Slater-Condon and other parameters from the levels.

Blaise, J.; Fred, M.; Gutmacher, R.G.

1984-08-01

52

Plutonium age dating reloaded  

NASA Astrophysics Data System (ADS)

Although the age determination of plutonium is and has been a pillar of nuclear forensic investigations for many years, additional research in the field of plutonium age dating is still needed and leads to new insights as the present work shows: Plutonium is commonly dated with the help of the 241Pu/241Am chronometer using gamma spectrometry; in fewer cases the 240Pu/236U chronometer has been used. The age dating results of the 239Pu/235U chronometer and the 238Pu/234U chronometer are scarcely applied in addition to the 240Pu/236U chronometer, although their results can be obtained simultaneously from the same mass spectrometric experiments as the age dating result of latter. The reliability of the result can be tested when the results of different chronometers are compared. The 242Pu/238U chronometer is normally not evaluated at all due to its sensitivity to contamination with natural uranium. This apparent 'weakness' that renders the age dating results of the 242Pu/238U chronometer almost useless for nuclear forensic investigations, however turns out to be an advantage looked at from another perspective: the 242Pu/238U chronometer can be utilized as an indicator for uranium contamination of plutonium samples and even help to identify the nature of this contamination. To illustrate this the age dating results of all four Pu/U clocks mentioned above are discussed for one plutonium sample (NBS 946) that shows no signs of uranium contamination and for three additional plutonium samples. In case the 242Pu/238U chronometer results in an older 'age' than the other Pu/U chronometers, contamination with either a small amount of enriched or with natural or depleted uranium is for example possible. If the age dating result of the 239Pu/235U chronometer is also influenced the nature of the contamination can be identified; enriched uranium is in this latter case a likely cause for the missmatch of the age dating results of the Pu/U chronometers.

Sturm, Monika; Richter, Stephan; Aregbe, Yetunde; Wellum, Roger; Mayer, Klaus; Prohaska, Thomas

2014-05-01

53

4. VIEW OF PLUTONIUM CANISTER ON CHAINVEYOR. SCRAP PLUTONIUM WAS ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

4. VIEW OF PLUTONIUM CANISTER ON CHAINVEYOR. SCRAP PLUTONIUM WAS COLLECTED INTO CANS AT INDIVIDUAL WORKSTATIONS. THE CANS WERE TRANSFERRED VIA THE CHAIN CONVEYOR TO A WORKSTATION IN MODULE C WHERE THE MATERIAL WAS COMPRESSED INTO BRIQUETTES FOR LATER USE. (6/20/93) - Rocky Flats Plant, Plutonium Manufacturing Facility, North-central section of Plant, just south of Building 776/777, Golden, Jefferson County, CO

54

Surprising Coordination for Plutonium in the First Plutonium (III) Borate  

SciTech Connect

The first plutonium(III) borate, Pu{sub 2}[B{sub 12}O{sub 18}(OH){sub 4}Br{sub 2}(H{sub 2}O){sub 3}]·0.5H{sub 2}O, has been prepared by reacting plutonium(III) with molten boric acid under strictly anaerobic conditions. This compound contains a three-dimensional polyborate network with triangular holes that house the plutonium(III) sites. The plutonium sites in this compound are 9- and 10-coordinate and display atypical geometries.

Wang, Shuao; Alekseev, Evgeny V.; Depmeier, Wulf; Albrecht-Schmitt, Thomas E.

2011-01-01

55

Dissolution of Plutonium Metal in 8-10 M Nitric Acid.  

National Technical Information Service (NTIS)

The H-Canyon facility will be used to dissolve Pu metal for subsequent purification and conversion to plutonium dioxide (PuO(sub 2)) using Phase II of HB-Line. To support the new mission, the development of a Pu metal dissolution flowsheet which utilizes ...

R. Pierce, T. Rudisill

2012-01-01

56

Method for dissolving hard-to-dissolve thorium and/or plutonium oxides  

SciTech Connect

Method for dissolving hard-to-dissolve thorium and/or plutonium oxides, especially dioxides such as ThO2, PuO2 or (U/Pu)O2 mixed oxides by heating the oxides in a hermetically sealed vessel in fluoride-free nitric acid. The use of a gas atmosphere containing oxygen in the sealed vessel is advantageous.

Ledebrink, F.-W.; Rosenkranz, W.; Stoll, W.

1985-07-09

57

Manufacturing of Plutonium Tensile Specimens  

SciTech Connect

Details workflow conducted to manufacture high density alpha Plutonium tensile specimens to support Los Alamos National Laboratory's science campaigns. Introduces topics including the metallurgical challenge of Plutonium and the use of high performance super-computing to drive design. Addresses the utilization of Abaqus finite element analysis, programmable computer numerical controlled (CNC) machining, as well as glove box ergonomics and safety in order to design a process that will yield high quality Plutonium tensile specimens.

Knapp, Cameron M [Los Alamos National Laboratory

2012-08-01

58

Welding Plutonium Storage Containers  

SciTech Connect

The outer can welder (OCW) in the FB-Line Facility at the Savannah River Site (SRS) is a Gas Tungsten Arc Weld (GTAW) system used to create outer canisters compliant with the Department of Energy 3013 Standard, DOE-STD-3013-2000, Stabilization, Packaging, and Storage of Plutonium-Bearing Materials. The key welding parameters controlled and monitored on the outer can welder Data Acquisition System (DAS) are weld amperage, weld voltage, and weld rotational speed. Inner 3013 canisters from the Bagless Transfer System that contain plutonium metal or plutonium oxide are placed inside an outer 3013 canister. The canister is back-filled with helium and welded using the outer can welder. The completed weld is screened to determine if it is satisfactory by reviewing the OCW DAS key welding parameters, performing a helium leak check, performing a visual examination by a qualified weld inspector, and performing digital radiography of the completed weld. Canisters with unsatisfactory welds are cut open and repackaged. Canisters with satisfactory welds are deemed compliant with the 3013 standard for long-term storage.

HUDLOW, SL

2004-04-20

59

Carbon dioxide  

NSDL National Science Digital Library

Bubbles are an indicator of a chemical reaction. An indicator is an object, material, or organism that tells you if a specific substance is present. In the sugar test, carbon dioxide gas release is an indicator that yeast is using sugar to grow. The more gas produced, the more sugar a specific substance contains.

Arie Melamed-Katz (None;)

2007-06-19

60

Raman spectroscopy of plutonium dioxide and related materials  

NASA Astrophysics Data System (ADS)

Evidence to support the Raman assignments of the 1LO (578 cm-1) and 2LO (1158 cm-1) lattice vibrations for PuO2 material is presented. The T2g signal is established at 476 ± 2 cm-1 in agreement with literature values. An increase of the 1LO band and an increase of the unit cell lattice parameter with ageing in our samples are found not to be a consequence of PuO2+x formation but rather a result of simple lattice defects due to radiation damage. The Raman spectrum of AnO2(OH)2?xH2O (An = Np, Pu) and laser induced decomposition products suggest that the transition to AnO2 involves Np2O5 for neptunium but no such analogue could be detected for Pu. The presence of a band around 1150 ± 10 cm-1 for a range of MO2 fluorite structures (CeO2, ThO2, UO2, NpO2 and PuO2) suggests that this band is not derived from crystal field electronic f-f transitions as proposed previously and supports recent suggestions that it is the first overtone of the 1LO lattice vibration. The spectrum of PuO2 is taken across a wide wavenumber range (200-4000 cm-1) and additional signals (2116 and 2611 cm-1) not previously reported have been observed but are not yet assigned with confidence.

Sarsfield, Mark J.; Taylor, Robin J.; Puxley, Christopher; Steele, Helen M.

2012-08-01

61

The growth and evolution of thin oxide films on delta-plutonium surfaces  

SciTech Connect

The common oxides of plutonium are the dioxide (PuO{sub 2}) and the sesquioxide (Pu{sub 2}O{sub 3}). The structure of an oxide on plutonium metal under air at room temperature is typically described as a thick PuO{sub 2} film at the gas-oxide interface with a thinner PuO{sub 2} film near the oxide-metal substrate interface. In a reducing environment, such as ultra high vacuum, the dioxide (Pu{sup 4+}; O/Pu = 2.0) readily converts to the sesquioxide (Pu{sup 3+}; O/Pu = 1.5) with time. In this work, the growth and evolution of thin plutonium oxide films is studied with x-ray photoelectron spectroscopy (XPS) under varying conditions. The results indicate that, like the dioxide, the sesquioxide is not stable on a very clean metal substrate under reducing conditions, resulting in substoichiometric films (Pu{sub 2}O{sub 3-y}). The Pu{sub 2}O{sub 3-y} films prepared exhibit a variety of stoichiometries (y = 0.2-1) as a function of preparation conditions, highlighting the fact that caution must be exercised when studying plutonium oxide surfaces under these conditions and interpreting resulting data.

Garcia Flores, Harry G [Los Alamos National Laboratory; Pugmire, David L [Los Alamos National Laboratory

2009-01-01

62

Cost-benefit analysis of unfired PuO/sub 2/ pellets as an alternative plutonium shipping form  

SciTech Connect

A limited cost-benefit evaluation was performed concerning use of unfired plutonium dioxide pellets as a shipping form. Two specific processing operations are required for this use, one to form the pellet (pelletizing) and a second to reconstitute an acceptable powder upon receipt (reconstitution). The direct costs for the pelletizing operation are approximately $208,000 for equipment and its installation and $122 per kg of plutonium processed (based upon a 20-kg plutonium/day facility). The direct costs for reconstitution are approximately $90,000 for equipment and its installation and $81 per kg of plutonium processed. The indirect cost considered was personnel exposure from these operations. Whole body exposures ranged from 0.04 man-rem per 100 kg of low-exposure plutonium reconstituted to 0.9 man-rem per 100 kg of average-exposure plutonium pelletized. Hand exposures were much higher - 17 man-rem power 100 kg of low-exposure plutonium reconstituted to 67 man-rem per 100 kg of average plutonium pelletized. The principal benefit is a potential twentyfold reduction of airborne release in the event of an accident. An experimental plan is outlined to fill the data gaps uncovered during this study in the areas of pelletizing and reconstitution process parameters and pellet response behavior to accident-generated stresses. A study to enhance the containment potential of the inner packaging used during shipment is also outlined.

Mishima, J.; Brackenbush, L.W.; Libby, R.A.; Soldat, K.L.; White, G.D.

1983-10-01

63

Low temperature oxidation of plutonium  

SciTech Connect

The initial oxidation of gallium stabilized {delta}-plutonium metal at 193 K has been followed using x-ray photoelectron spectroscopy. On exposure to Langmuir quantities of oxygen, plutonium rapidly forms a trivalent oxide followed by a tetravalent plutonium oxide. The growth modes of both oxides have been determined. Warming the sample in vacuum, the tetravalent oxide reduces to the trivalent oxide. The kinetics of this reduction reaction have followed and the activation energy has been determined to be 38.8 kJ mol{sup -1}.

Nelson, Art J. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); Roussel, Paul [AWE, Aldermaston, Reading, Berkshire, RG7 4PR (United Kingdom)

2013-05-15

64

Assessment of the risk of transporting plutonium dioxide and liquid plutonium nitrate by train  

Microsoft Academic Search

The risk analysis model is applied to the assessment of the risk of Pu releases due to transportation accidents and package misclosure and degradation. The transport system and accident environment are described and release sequences postulated. Results are related to the early 1980s, when Pu shipments are expected to be more frequent (18 metric tons Pu shipped by rail per

D. K. Davis; S. W. Heaberlin; J. F. Johnson; P. L. Peterson

1977-01-01

65

Effects of water vapor on the surface chemistry of calcined plutonium peroxide as determined by nitrogen adsorption  

SciTech Connect

The amount of water vapor readsorbed on plutonium dioxide, following calcination of plutonium peroxide at 400/sup 0/C, was measured for 14 oxide samples. It was determined that this adsorbed water decreased nitrogen adsorption and thus the specific surface area of the oxide, as determined by the method derived by Brunauer, Emmett, and Teller (BET) was also reduced. As water was desorbed by heating, the surface area of the plutonium dioxide increased until the temperature reached 500/sup 0/C. Further heating to 600/sup 0/C resulted in a decrease in the surface area. The adsorption potential for nitrogen at -196/sup 0/C also increased as the amount of chemisorbed water decreased. The total pore volume of the oxides was not significantly changed by the adsorbed water.

Stakebake, J.L.; Robinson, H.H.

1983-09-01

66

The vaporisation behaviour of americium dioxide by use of mass spectrometry  

NASA Astrophysics Data System (ADS)

The vaporisation behaviour of americium dioxide in vacuum at high temperatures up to 2400 K has been studied. A Knudsen cell coupled with a mass spectrometer was used to perform vapour pressure measurements. The ionisation efficiency curves of Am +, AmO + and AmO2+ were simultaneously recorded. Appearance potentials of the key molecular species were determined by varying the energy of the ionising electrons at constant temperature. The partial and total vapour pressures above the americium oxide samples measured as a function of the temperature. The results on the vapour pressure of the pure americium dioxide samples were discussed together with the available literature data on plutonium dioxide containing small amounts of americium. Additional measurements have been performed on a mixed dioxide sample of plutonium containing 6.1 wt.% americium.

Gotcu-Freis, P.; Colle, J.-Y.; Hiernaut, J.-P.; Konings, R. J. M.

2011-02-01

67

Plutonium focus area  

SciTech Connect

To ensure research and development programs focus on the most pressing environmental restoration and waste management problems at the U.S. Department of Energy (DOE), the Assistant Secretary for the Office of Environmental Management (EM) established a working group in August 1993 to implement a new approach to research and technology development. As part of this new approach, EM developed a management structure and principles that led to the creation of specific Focus Areas. These organizations were designed to focus the scientific and technical talent throughout DOE and the national scientific community on the major environmental restoration and waste management problems facing DOE. The Focus Area approach provides the framework for intersite cooperation and leveraging of resources on common problems. After the original establishment of five major Focus Areas within the Office of Technology Development (EM-50, now called the Office of Science and Technology), the Nuclear Materials Stabilization Task Group (EM-66) followed the structure already in place in EM-50 and chartered the Plutonium Focus Area (PFA). The following information outlines the scope and mission of the EM, EM-60, and EM-66 organizations as related to the PFA organizational structure.

NONE

1996-08-01

68

Plutonium solution analyzer  

SciTech Connect

A fully automated analyzer has been developed for plutonium solutions. It was assembled from several commercially available modules, is based upon segmented flow analysis, and exhibits precision about an order of magnitude better than commercial units (0.5%-O.05% RSD). The system was designed to accept unmeasured, untreated liquid samples in the concentration range 40-240 g/L and produce a report with sample identification, sample concentrations, and an abundance of statistics. Optional hydraulics can accommodate samples in the concentration range 0.4-4.0 g/L. Operating at a typical rate of 30 to 40 samples per hour, it consumes only 0.074 mL of each sample and standard, and generates waste at the rate of about 1.5 mL per minute. No radioactive material passes through its multichannel peristaltic pump (which remains outside the glovebox, uncontaminated) but rather is handled by a 6-port, 2-position chromatography-type loop valve. An accompanying computer is programmed in QuickBASIC 4.5 to provide both instrument control and data reduction. The program is truly user-friendly and communication between operator and instrument is via computer screen displays and keyboard. Two important issues which have been addressed are waste minimization and operator safety (the analyzer can run in the absence of an operator, once its autosampler has been loaded).

Burns, D.A.

1994-09-01

69

Plutonium removal limit for the disposition of plutonium-bearing materials  

Microsoft Academic Search

Recent changes in world politics have resulted in the United States reducing its nuclear weapons and stopping plutonium production. Prior plutonium production, dismantling warheads, and decontamination and decommissioning some facilities have produced plutonium-bearing materials which must continue to be managed. As each lot of material is processed, the processor must decide whether to remove the plutonium before discarding the material

W. C. White; B. Mowery; R. Felt; F. King; J. D. Hurley

1992-01-01

70

Design and fabrication of SGS plutonium standards  

SciTech Connect

This paper describes our experience of fabricating four sets of plutonium segmented gamma scanner (SGS) can standards. The fabrication involves careful planning, meticulous execution in weighing the plutonium oxide while minimizing contamination, chemical analyses by three different national laboratories to get accurate and independent plutonium concentrations, vertical scanning to assure mixing of the plutonium and the diluent, and finally the nondestructive verification measurement. By following these steps, we successfully fabricated 4 sets or 20 SGS can standards. 4 refs., 5 figs., 3 tabs.

Hsue, S.T.; Simmonds, S.M.; Longmire, V.L.; Long, S.M.

1991-01-01

71

Production of Plutonium Metal from Aqueous Solutions  

SciTech Connect

The primary separation of plutonium from irradiated uranium by the Purex solvent extraction process at the Savannah River Plant produces a dilute plutonium solution containing residual fission products and uranium. A cation exchange process is used for concentration and further decontamination of the plutonium, as the first step in the final preparation of metal. This paper discusses the production of plutonium metal from the aqueous solutions.

Orth, D.A.

2003-01-16

72

Estimating China's Production of Plutonium for Weapons  

Microsoft Academic Search

This article discusses the history of China's production of plutonium for nuclear weapons, and uses that history and analogies to the production process in the United States and Russia to estimate the amount of plutonium China produced at its two known facilities. That analysis leads to an estimate that China produced 2 to 5 tonnes of plutonium at these facilities

David Wright; Lisbeth Gronlund

2003-01-01

73

Robot vision system for remote plutonium disposition  

Microsoft Academic Search

Tons of weapons-usable plutonium has been declared surplus to the national security needs of the United States. The Plutonium Immobilization Program (PIP) is a US Department of Energy sponsored program to place excess plutonium in a stable form and make it unattractive for reuse. A vision system was developed as part of PIP robotic and remote systems development. This vision

Kriikku; Eric M. Kriikku

2000-01-01

74

Method of separating thorium from plutonium  

DOEpatents

A method is described for chemically separating plutonium from thorium. Plutonium and thorium to be separated are dissolved in an aqueous feed solution, preferably as the nitrate salts. The feed solution is acidified and sodium nitrite is added to the solution to adjust the valence of the plutonium to the +4 state. A chloride salt, preferably sodium chloride, is then added to the solution to induce formation of an anionic plutonium chloride complex. The anionic plutonium chloride complex and the thorium in solution are then separated by ion exchange on a strong base anion exchange column.

Clifton, D.G.; Blum, T.W.

1984-07-10

75

Hanford-derived plutonium in Columbia River sediments  

Microsoft Academic Search

Mass spectrometry data on plutonium isolated from Columbia River sediments exhibit mean ratios of plutonium-240 to plutonium-242 consistent with those observed for integrated global fallout. Ratios of plutonium-240 to plutonium-239 show marked deviations from accepted fallout values, suggesting a second source of plutonium-239. This additional plutonium-239 arises from the decay of neptunium-239 produced in reactor effluent water from the old

T. M. Beasley; L. A. Ball; J. E. Andrews; J. E. Halverson

1981-01-01

76

Plutonium immobilization form evaluation  

SciTech Connect

The 1994 National Academy of Sciences study and the 1997 assessment by DOE`s Office of Nonproliferation and National Security have emphasized the importance of the overall objectives of the Plutonium Disposition Program of beginning disposition rapidly. President Clinton and other leaders of the G-7 plus one (`Political Eight`) group of states, at the Moscow Nuclear Safety And Security Summit in April 1996, agreed on the objectives of accomplishing disposition of excess fissile material as soon as practicable. To meet these objectives, DOE has laid out an aggressive schedule in which large-scale immobilization operations would begin in 2005. Lawrence Livermore National Laboratory (LLNL), the lead laboratory for the development of Pu immobilization technologies for the Department of Energy`s Office of Fissile Materials Disposition (MD), was requested by MD to recommend the preferred immobilization form and technology for the disposition of excess weapons-usable Pu. In a series of three separate evaluations, the technologies for the candidate glass and ceramic forms were compared against criteria and metrics that reflect programmatic and technical objectives: (1) Evaluation of the R&D and engineering data for the two forms against the decision criteria/metrics by a technical evaluation panel comprising experts from within the immobilization program. (2) Integrated assessment by LLNL immobilization management of the candidate technologies with respect to the weighted criteria and other programmatic objectives, leading to a recommendation to DOE/MD on the preferred technology based on technical factors. (3) Assessment of the decision process, evaluation, and recommendation by a peer review panel of independent experts. Criteria used to assess the relative merits of the immobilization technologies were a subset of the criteria previously used by MD to choose among disposition options leading to the Programmatic Environmental Impact Statement and Record of Decision for the Storage and Disposition of Weapons-Usable Fissile Materials, January 1997. Criteria were: (1) resistance to Pu theft, diversion, and recovery by a terrorist organization or rogue nation; (2) resistance to recovery and reuse by host nation; (3) technical viability, including technical maturity, development risk, and acceptability for repository disposal; (4) environmental, safety, and health factors; (5) cost effectiveness; and (6) timeliness. On the basis of the technical evaluation and assessments, in September, 1997, LLNL recommended to DOE/MD that ceramic technologies be developed for deployment in the planned Pu immobilization plant.

Gray, L. W., LLNL

1998-02-13

77

Plutonium from Chernobyl in Poland  

Microsoft Academic Search

Samples of coniferous forest litter collected in POland, of known ?-emitters activity, have been analysed for ? emitting plutonium isotopes. Specific as well as surface activities of the samples have been determined. Chernobyl and global fallout components have been distinguished for each sample. The observed maximum surface activity for Chernobyl fallout is above 25 Bq m?2 (for all ?-emitting Pu

Jerzy W. Mietelski

1995-01-01

78

Plutonium Recycle: The Fateful Step  

ERIC Educational Resources Information Center

Calls attention to the fact that if the Atomic Energy Commission proceeds with its plans to authorize the nuclear power industry to use plutonium as a fuel in commercial nuclear reactors around the country, this will result in a dramatic escalation in the risks posed by nuclear power. (PEB)

Speth, J. Gustave; And Others

1974-01-01

79

Carbon dioxide power cycle  

Microsoft Academic Search

An improved direct fired power system generating and employing a combustion gas which includes carbon dioxide or a working fluid including a combustion chamber for burning a mixture which includes oxygen, carbonaceous fuel and recycled carbon dioxide working fluid at a first pressure of above 1100 PSI thereby providing a combustion gas which includes carbon dioxide and water at substantially

Osgerby

1985-01-01

80

Nitrogen dioxide detection  

DOEpatents

Method and apparatus for detecting the presence of gaseous nitrogen dioxide and determining the amount of gas which is present. Though polystyrene is normally an insulator, it becomes electrically conductive in the presence of nitrogen dioxide. Conductance or resistance of a polystyrene sensing element is related to the concentration of nitrogen dioxide at the sensing element.

Sinha, Dipen N. (Los Alamos, NM); Agnew, Stephen F. (Los Alamos, NM); Christensen, William H. (Buena Park, CA)

1993-01-01

81

The radiological hazard of plutonium isotopes and specific plutonium mixtures  

SciTech Connect

The US Department of Energy defines the hazard categories of its nuclear facilities based upon the potential for accidents to have significant effects on specific populations and the environment. In this report, the authors consider the time dependence of hazard category 2 (significant on-site effects) for facilities with inventories of plutonium isotopes and specific weapons-grade and heat-source mixtures of plutonium isotopes. The authors also define relative hazard as the reciprocal of the hazard category 2 threshold value and determine its time dependence. The time dependence of both hazard category 2 thresholds and relative hazards are determined and plotted for 10,000 years to provide useful information for planning long-term storage or disposal facilities.

Heindel, G.; Clow, J.; Inkret, W.; Miller, G.

1995-11-01

82

Multi-generational stewardship of plutonium  

SciTech Connect

The post-cold war era has greatly enhanced the interest in the long-term stewardship of plutonium. The management of excess plutonium from proposed nuclear weapons dismantlement has been the subject of numerous intellectual discussions during the past several years. In this context, issues relevant to long-term management of all plutonium as a valuable energy resource are also being examined. While there are differing views about the future role of plutonium in the economy, there is a recognition of the environmental and health related problems and proliferation potentials of weapons-grade plutonium. The long-term management of plutonium as an energy resource will require a new strategy to maintain stewardship for many generations to come.

Pillay, K.K.S. [Los Alamos National Lab., NM (United States). Nuclear Materials Technology Div.

1997-10-01

83

Air transport of plutonium metal: content expansion initiative for the plutonium air transportable (PAT01) packaging  

SciTech Connect

The National Nuclear Security Administration (NNSA) has submitted an application to the Nuclear Regulatory Commission (NRC) for the air shipment of plutonium metal within the Plutonium Air Transportable (PAT-1) packaging. The PAT-1 packaging is currently authorized for the air transport of plutonium oxide in solid form only. The INMM presentation will provide a limited overview of the scope of the plutonium metal initiative and provide a status of the NNSA application to the NRC.

Caviness, Michael L [Los Alamos National Laboratory; Mann, Paul T [NNSA/ALBUQUERQUE; Yoshimura, Richard H [SNL

2010-01-01

84

Air transport of plutonium metal : content expansion initiative for the Plutonium Air Transportable (PAT-1) packaging.  

SciTech Connect

The National Nuclear Security Administration (NNSA) has submitted an application to the Nuclear Regulatory Commission (NRC) for the air shipment of plutonium metal within the Plutonium Air Transportable (PAT-1) packaging. The PAT-1 packaging is currently authorized for the air transport of plutonium oxide in solid form only. The INMM presentation will provide a limited overview of the scope of the plutonium metal initiative and provide a status of the NNSA application to the NRC.

Mann, Paul T. (National Nuclear Security Administration); Caviness, Michael L. (Los Alamos National Laboratory); Yoshimura, Richard Hiroyuki

2010-06-01

85

Plutonium Immobilization Can Loading Concepts  

SciTech Connect

The Plutonium Immobilization Facility will encapsulate plutonium in ceramic pucks and seal the pucks inside welded cans. Remote equipment will place these cans in magazines and the magazines in a Defense Waste Processing Facility (DWPF) canister. The DWPF will fill the canister with glass for permanent storage. This report discusses five can loading conceptual designs and the lists the advantages and disadvantages for each concept. This report identifies loading pucks into cans and backfilling cans with helium as the top priority can loading development areas. The can loading welder and cutter are very similar to the existing Savannah River Site (SRS) FB-Line bagless transfer welder and cutter and thus they are a low priority development item.

Kriikku, E. [Westinghouse Savannah River Company, AIKEN, SC (United States); Ward, C.; Stokes, M.; Randall, B.; Steed, J.; Jones, R.; Hamilton, L.; Rogers, L.; Fiscus, J.; Dyches, G.

1998-05-01

86

Alpha-plutonium's Grüneisen parameter.  

PubMed

Reported Grüneisen parameters ? of alpha-plutonium range from 3.0 to 9.6, which is remarkable because typical Grüneisen parameter uncertainty seldom exceeds ± 0.5. Our six new estimates obtained by different methods range from 3.2 to 9.6. The new estimates arise from Grüneisen's rule, from Einstein model and Debye model fits to low-temperature ?V/V, from the bulk modulus temperature dependence, from the zero-point-energy contribution to the bulk modulus, and from another Grüneisen relationship whereby ? is estimated from only the bulk modulus and volume changes with temperature (or pressure). We disregard several high estimates because of the itinerant-localized 5f-electron changes during temperature changes and pressure changes. Considering all these estimates, for alpha-plutonium, we recommend ? = 3.7 ± 0.4, slightly high compared with values for all elemental metals. PMID:21386421

Ledbetter, Hassel; Lawson, Andrew; Migliori, Albert

2010-04-28

87

Decomposition kinetics of plutonium hydride  

Microsoft Academic Search

Kinetic data for decomposition of PuH⁠ââ provides insight into a possible mechanism for the hydriding and dehydriding reactions of plutonium. The fact that the rate of the hydriding reaction, K\\/sub H\\/, is proportional to P¹² and the rate of the dehydriding process, K\\/sub D\\/, is inversely proportional to P¹² suggests that the forward and reverse reactions proceed by opposite

J. M. Haschke; J. L. Stakebake

1979-01-01

88

Plutonium Immobilization Program cold pour tests  

Microsoft Academic Search

The Plutonium Immobilization Program (PIP) is a joint venture between the Savannah River Site, Lawrence Livermore National Laboratory, Argonne National Laboratory, and Pacific Northwest National Laboratory to carry out the disposition of excess weapons-grade plutonium. This program uses the can-in-canister (CIC) approach. CIC involves encapsulating plutonium in ceramic forms (or pucks), placing the pucks in sealed stainless steel cans, placing

G. L. Hovis; M. W. Stokes; M. E. Smith; J. W. Wong

1999-01-01

89

LANL Plutonium-Processing Facilities National Security  

E-print Network

- tinide chemistry; nuclear materials separation, processing, and recovery; plutonium metallurgy, preparation, casting, fabrication, and recovery; machining and metallurgy laboratories; and de- structive

90

Electrochemical investigation into the mechanism of plutonium reduction in electrorefining  

Microsoft Academic Search

Currently impure plutonium metal is purified at Los Alamos National Laboratory by a molten salt electrorefining process. Electrorefining is an effective method for producing high-purity plutonium metal (> 99.95%). In general this process involves the oxidation of impure plutonium metal from a molten plutonium anode or a solvent metal\\/plutonium anode, transport of plutonium ions through a molten salt electrolyte, and

L. E. McCurry; G. M. M. Moy

1987-01-01

91

A summary of volatile impurity measurements and gas generation studies on MISSTD-1, a high-purity plutonium oxide produced by low-temperature calcination of plutonium oxalate  

SciTech Connect

Plutonium dioxide of high specific surface area was subjected to long-term tests of gas generation in sealed containers. The material preparation and the storage conditions were outside the bounds of acceptable parameters defined by DOE-STD-3013-2012 in that the material was stabilized to a lower temperature than required and had higher moisture content than allowed. The data provide useful information for better defining the bounding conditions for safe storage. Net increases in internal pressure and transient increases in H{sub 2} and O{sub 2} were observed, but were well within the bounds of gas compositions previously shown to not threaten integrity of 3013 containers.

Berg, John M. [Los Alamos National Laboratory; Narlesky, Joshua E. [Los Alamos National Laboratory; Veirs, Douglas K. [Los Alamos National Laboratory

2012-06-08

92

The carbon dioxide cycle  

USGS Publications Warehouse

The seasonal CO2 cycle on Mars refers to the exchange of carbon dioxide between dry ice in the seasonal polar caps and gaseous carbon dioxide in the atmosphere. This review focuses on breakthroughs in understanding the process involving seasonal carbon dioxide phase changes that have occurred as a result of observations by Mars Global Surveyor. ?? 2004 COSPAR. Published by Elsevier Ltd. All rights reserved.

James, P.B.; Hansen, G.B.; Titus, T.N.

2005-01-01

93

Burning weapons-grade plutonium in reactors  

Microsoft Academic Search

As a result of massive reductions in deployed nuclear warheads, and their subsequent dismantlement, large quantities of surplus weapons- grade plutonium will be stored until its ultimate disposition is achieved in both the US and Russia. Ultimate disposition has the following minimum requirements: (1) preclude return of plutonium to the US and Russian stockpiles, (2) prevent environmental damage by precluding

1993-01-01

94

Japan's spent fuel and plutonium management challenge  

Microsoft Academic Search

Japan's commitment to plutonium recycling has been explicitly stated in its long-term program since 1956. Despite the clear cost disadvantage compared with direct disposal or storage of spent fuel, the Rokkasho reprocessing plant started active testing in 2006. Japan's cumulative consumption of plutonium has been only 5tons to date and its future consumption rate is still uncertain. But once the

Tadahiro Katsuta; Tatsujiro Suzuki

2011-01-01

95

Plutonium Immobilization Program: Can-in-Canister  

SciTech Connect

'The end of the cold war brought about a potential new danger, the existence of surplus weapons grade plutonium in the U.S. and Russia. Bilateral disposition programs provide the preferred long-term solution. This paper presents an overview of the U.S. approach to plutonium immobilization using the Can-in-Canister technology.'

Rankin, D.T.

1999-07-14

96

Plutonium Finishing Plant operational readiness review  

Microsoft Academic Search

This plan describes the readiness review process to be used to meet the objectives to support the restart of the Plutonium Finishing Plant (PFP) to convert the chemically-acting plutonium-bearing materials to a form suitable for processing in the remote mechanical C'' (RMC) line. The scope of this plan will cover the restart readiness review needs of the PFP Material Stabilization

Eschenbaum

1992-01-01

97

Reactive sintering of plutonium-bearing titanates.  

SciTech Connect

Titanate ceramics are being developed for the immobilization of weapons-grade plutonium. These multi-phase ceramics are intended to be both corrosion and proliferation resistant. Reactive sintering techniques were refined to reproducibly provide titanate ceramics for further characterization and testing. Plutonium-bearing pyrochlore-rich composites were consolidated to greater than 90% of their theoretical density.

Hash, M. C.

1999-06-24

98

Plutonium Uptake and Distribution in Mammalian Cells: Molecular vs Polymeric Plutonium  

PubMed Central

Purpose To study the cellular responses to molecular and polymeric forms of plutonium using PC12 cells derived from rat adrenal glands. Materials and methods Serum starved PC12 cells were exposed to polymeric and molecular forms of plutonium for three hours. Cells were washed with 10 mM EGTA, 100 mM NaCl at pH 7.4 to remove surface sorbed plutonium. Localization of plutonium in individual cell was quantitatively analyzed by synchrotron X-ray fluorescence (XRF) microscopy. Results Molecular plutonium complexes introduced to cell growth media in the form of NTA, citrate, or transferrin complexes were taken up by PC12 cells, and mostly co-localized with iron within the cells. Polymeric plutonium prepared separately was not internalized by PC12 cells but it was always found on the cell surface as big agglomerates; however polymeric plutonium formed in situ was mostly found within the cells as agglomerates. Conclusions PC12 cells can differentiate molecular and polymeric forms of plutonium. Molecular plutonium is taken up by PC12 cells and mostly co-localized with iron but aged polymeric plutonium is not internalized by the cells. PMID:21770702

ARYAL, BAIKUNTHA P.; GORMAN-LEWIS, DREW; PAUNESKU, TATJANA; WILSON, RICHARD E.; LAI, BARRY; VOGT, STEFAN; WOLOSCHAK, GAYLE E.; JENSEN, MARK P.

2013-01-01

99

Alpha radiation effects on weapons-grade plutonium encapsulating materials  

Microsoft Academic Search

The scientific understanding of material problems in the long-term storage of plutonium pits is investigated using experimental and theoretical models. The durability of the plutonium pit depends on the integrity of the metal cladding that encapsulates the plutonium. Given sufficient time, the energetic alpha particles (helium nuclei) produced by nuclear decay of the plutonium would degrade the mechanical strength of

Mehmet Saglam

2000-01-01

100

TERTIARY AMINE EXTRACTION OF PLUTONIUM FROM NITRIC ACID SOLUTIONS  

Microsoft Academic Search

Data are presented to show the effect of pertinent variables on the ; extraction of plutonium. The extraction of plutonium(III) and (VI) is shown to ; be small. The data on the extraction of plutonium(IV) by several amines are ; presented and discussed. Some experiments on the effect of the organic diluent ; on the solubility of the plutonium(IV)-amine complex

1958-01-01

101

Plutonium focus area. Technology summary  

SciTech Connect

The Assistant Secretary for the Office of Environmental Management (EM) at the U.S. Department of Energy (DOE) chartered the Plutonium Focus Area (PFA) in October 1995. The PFA {open_quotes}...provides for peer and technical reviews of research and development in plutonium stabilization activities...{close_quotes} In addition, the PFA identifies and develops relevant research and technology. The purpose of this document is to focus attention on the requirements used to develop research and technology for stabilization, storage, and preparation for disposition of nuclear materials. The PFA Technology Summary presents the approach the PFA uses to identify, recommend, and review research. It lists research requirements, research being conducted, and gaps where research is needed. It also summarizes research performed by the PFA in the traditional research summary format. This document encourages researchers and commercial enterprises to do business with PFA by submitting research proposals or {open_quotes}white papers.{close_quotes} In addition, it suggests ways to increase the likelihood that PFA will recommend proposed research to the Nuclear Materials Stabilization Task Group (NMSTG) of DOE.

NONE

1997-09-01

102

Automated amperometric plutonium assay system  

SciTech Connect

The amperometric titration for plutonium assay has been used in the nuclear industry for over twenty years and has been in routine use at the Hanford Engineering Development Laboratory since 1976 for the analysis of plutonium oxide and mixed oxide fuel material for the Fast Flux Test Facility. It has proven itself to be an accurate and reliable method. The method may be used as a direct end point titration or an excess of titrant may be added and a back titration performed to aid in determination of the end point. Due to the slowness of the PuVI-FeII reaction it is difficult to recognize when the end point is being approached and is very time consuming if the current is allowed to decay to the residual value after each titrant addition. For this reason the back titration in which the rapid FeII-CrVI reaction occurs is used by most laboratories. The back titration is performed by the addition of excess ferrous solution followed by two measured aliquots of standard dichromate with measurement of cell current after each addition.

Burt, M.C.

1985-01-01

103

HENC performance evaluation and plutonium calibration  

SciTech Connect

The authors have designed a high-efficiency neutron counter (HENC) to increase the plutonium content in 200-L waste drums. The counter uses totals neutron counting, coincidence counting, and multiplicity counting to determine the plutonium mass. The HENC was developed as part of a Cooperative Research and Development Agreement between the Department of Energy and Canberra Industries. This report presents the results of the detector modifications, the performance tests, the add-a-source calibration, and the plutonium calibration at Los Alamos National Laboratory (TA-35) in 1996.

Menlove, H.O.; Baca, J.; Pecos, J.M. [Los Alamos National Lab., NM (United States); Davidson, D.R.; McElroy, R.D.; Brochu, D.B. [Canberra Industries, Meriden, CT (United States)

1997-10-01

104

Plutonium Immobilization Can Loading Conceptual Design  

SciTech Connect

'The Plutonium Immobilization Facility will encapsulate plutonium in ceramic pucks and seal the pucks inside welded cans. Remote equipment will place these cans in magazines and the magazines in a Defense Waste Processing Facility (DWPF) canister. The DWPF will fill the canister with glass for permanent storage. This report discusses the Plutonium Immobilization can loading conceptual design and includes a process block diagram, process description, preliminary equipment specifications, and several can loading issues. This report identifies loading pucks into cans and backfilling cans with helium as the top priority can loading development areas.'

Kriikku, E.

1999-05-13

105

Weapons-grade plutonium dispositioning. Volume 4. Plutonium dispositioning in light water reactors  

SciTech Connect

This study is in response to a request by the Reactor Panel Subcommittee of the National Academy of Sciences (NAS) Committee on International Security and Arms Control (CISAC) to evaluate the feasibility of using plutonium fuels (without uranium) for disposal in existing conventional or advanced light water reactor (LWR) designs and in low temperature/pressure LWR designs that might be developed for plutonium disposal. Three plutonium-based fuel forms (oxides, aluminum metallics, and carbides) are evaluated for neutronic performance, fabrication technology, and material and compatibility issues. For the carbides, only the fabrication technologies are addressed. Viable plutonium oxide fuels for conventional or advanced LWRs include plutonium-zirconium-calcium oxide (PuO{sub 2}-ZrO{sub 2}-CaO) with the addition of thorium oxide (ThO{sub 2}) or a burnable poison such as erbium oxide (Er{sub 2}O{sub 3}) or europium oxide (Eu{sub 2}O{sub 3}) to achieve acceptable neutronic performance. Thorium will breed fissile uranium that may be unacceptable from a proliferation standpoint. Fabrication of uranium and mixed uranium-plutonium oxide fuels is well established; however, fabrication of plutonium-based oxide fuels will require further development. Viable aluminum-plutonium metallic fuels for a low temperature/pressure LWR include plutonium aluminide in an aluminum matrix (PuAl{sub 4}-Al) with the addition of a burnable poison such as erbium (Er) or europium (Eu). Fabrication of low-enriched plutonium in aluminum-plutonium metallic fuel rods was initially established 30 years ago and will require development to recapture and adapt the technology to meet current environmental and safety regulations. Fabrication of high-enriched uranium plate fuel by the picture-frame process is a well established process, but the use of plutonium would require the process to be upgraded in the United States to conform with current regulations and minimize the waste streams.

Sterbentz, J.W.; Olsen, C.S.; Sinha, U.P.

1993-06-01

106

What is plutonium stabilization, and what is safe storage of plutonium?  

SciTech Connect

The end of the cold war has resulted in the shutdown of nuclear weapons production and the start of dismantlement of significant numbers of nuclear weapons. This, in turn, is creating an inventory of plutonium requiring interim and long-term storage. A key question is, ``What is required for safe, multidecade, plutonium storage?`` The requirements for storage, in turn, define what is needed to stabilize the plutonium from its current condition into a form acceptable for interim and long-term storage. Storage requirements determine if research is required to (1) define required technical conditions for interim and long-term storage and (2) develop or improve current stabilization technologies. Storage requirements depend upon technical, policy, and economic factors. The technical issues are complicated by several factors. Plutonium in aerosol form is highly hazardous. Plutonium in water is hazardous. The plutonium inventory is in multiple chemical forms--some of which are chemically reactive. Also, some of the existing storage forms are clearly unsuitable for storage periods over a few years. Gas generation by plutonium compounds complicates storage: (1) all plutonium slowly decays creating gaseous helium and (2) the radiation from plutonium decay can initiate many chemical reactions-some of which generate significant quantities of gases. Gas generation can pressurize sealed storage packages. Last nuclear criticality must be avoided.

Forsberg, C.W.

1995-06-29

107

Uranium plutonium oxide fuels. [LMFBR  

SciTech Connect

Uranium plutonium oxide is the principal fuel material for liquid metal fast breeder reactors (LMFBR's) throughout the world. Development of this material has been a reasonably straightforward evolution from the UO/sub 2/ used routinely in the light water reactor (LWR's); but, because of the lower neutron capture cross sections and much lower coolant pressures in the sodium cooled LMFBR's, the fuel is operated to much higher discharge exposures than that of a LWR. A typical LMFBR fuel assembly is shown. Depending on the required power output and the configuration of the reactor, some 70 to 400 such fuel assemblies are clustered to form the core. There is a wide variation in cross section and length of the assemblies where the increasing size reflects a chronological increase in plant size and power output as well as considerations of decreasing the net fuel cycle cost. Design and performance characteristics are described.

Cox, C.M.; Leggett, R.D.; Weber, E.T.

1981-01-01

108

Plutonium focus area: Technology summary  

SciTech Connect

To ensure research and development programs focus on the most pressing environmental restoration and waste management problems at the U.S. Department of Energy (DOE), the Assistant Secretary for the Office of Environmental Management (EM) established a working group in August 1993 to implement a new approach to research and technology development. As part of this approach, EM developed a management structure and principles that led to creation of specific focus areas. These organizations were designed to focus scientific and technical talent throughout DOE and the national scientific community on major environmental restoration and waste management problems facing DOE. The focus area approach provides the framework for inter-site cooperation and leveraging of resources on common problems. After the original establishment of five major focus areas within the Office of Technology Development (EM-50), the Nuclear Materials Stabilization Task Group (NMSTG, EM-66) followed EM-50`s structure and chartered the Plutonium Focus Area (PFA). NMSTG`s charter to the PFA, described in detail later in this book, plays a major role in meeting the EM-66 commitments to the Defense Nuclear Facilities Safety Board (DNFSB). The PFA is a new program for FY96 and as such, the primary focus of revision 0 of this Technology Summary is an introduction to the Focus Area; its history, development, and management structure, including summaries of selected technologies being developed. Revision 1 to the Plutonium Focus Area Technology Summary is slated to include details on all technologies being developed, and is currently planned for release in August 1996. The following report outlines the scope and mission of the Office of Environmental Management, EM-60, and EM-66 organizations as related to the PFA organizational structure.

NONE

1996-03-01

109

International shipment of plutonium by air  

SciTech Connect

In support of the United States (US) Government`s decision to place excess plutonium oxide at the US Department of Energy`s (DOE) Hanford Site under International Atomic Energy Agency (IAEA) safeguards, the Department of State notified the Congress that a plutonium storage vault at the Plutonium Finishing Plant at the Hanford Site would be added to the eligible facilities list. As part of the preparations to transfer the plutonium oxide under IAEA safeguards, samples of the powder were taken from the inventory to be shipped to the IAEA headquarters in Vienna, Austria, for laboratory analysis. The analysis of these samples was of high priority, and the IAEA requested that the material be shipped by aircraft, the most expeditious method.

Mercado, J.E.; McGrogan, J.P.

1995-05-01

110

Plutonium Sphere Reflected by Reflected by Beryllium.  

National Technical Information Service (NTIS)

This experiment with an alpha-phase plutonium sphere reflected by beryllium was performed using the Planet critical assembly at the Los Alamos Critical Experiments Facility (LACEF). The beryllium reflector consisted of a pair of inner and outer hemisphere...

D. Loaiza, J. Hutchinson

2013-01-01

111

Carbonate Complexation of Plutonium(IV).  

National Technical Information Service (NTIS)

Plutonium(IV) carbonate complexes are expected to be of particular importance in typical groundwaters at the Yucca Mountain site of the candidate nuclear waste repository being studied by the Nevada Nuclear Waste Storage Investigations Project. The chemis...

D. E. Hobart, P. D. Palmer, T. W. Newton

1985-01-01

112

Plutonium finishing plant dangerous waste training plan  

SciTech Connect

This training plan describes general requirements, worker categories, and provides course descriptions for operation of the Plutonium Finish Plant (PFP) waste generation facilities, permitted treatment, storage and disposal (TSD) units, and the 90-Day Accumulation Areas.

ENTROP, G.E.

1999-05-24

113

Design and evaluation of plutonium electrorefining cells  

SciTech Connect

A plutonium electrorefining cell was designed for stationary furnace operation. This cell and the LANL electrorefining cell were evaluated. Results of this evaluation and comparison to existing production electrorefining at Rocky Flats are presented.

Not Available

1987-01-01

114

Zirconia ceramics for excess weapons plutonium waste  

Microsoft Academic Search

We synthesized a zirconia (ZrO2)-based single-phase ceramic containing simulated excess weapons plutonium waste. ZrO2 has large solubility for other metallic oxides. More than 20 binary systems AxOy–ZrO2 have been reported in the literature, including PuO2, rare-earth oxides, and oxides of metals contained in weapons plutonium wastes. We show that significant amounts of gadolinium (neutron absorber) and yttrium (additional stabilizer of

W. L. Gong; W. Lutze; R. C. Ewing

2000-01-01

115

Plutonium-238 processing at Savannah River Plant  

SciTech Connect

Plutonium-238 is produced by irradiating NpO/sub 2/-Al cermet slugs or tubes with neutrons. The neptunium-237 is produced as a by-product when natural or enriched uranium is irradiated with neutrons. The neptunium is separated by solvent extraction and ion exchange and precipitated as neptunium oxalate. Neptunium oxalate is calcined to neptunium oxide and fabricated into targets for irradiation. The irradiation conditions are controlled to produce plutonium with 80 to 90 wt % /sup 238/Pu.

Burney, G.A.

1983-01-01

116

Dangerous surplus. [Management of weapons plutonium  

Microsoft Academic Search

As a result of existing arms control reduction commitments, approximately 50 metric tons of weapon-grade plutonium is expected to become surplus in the United States--and a similar or larger amount in Russia--over the next 10 years. It is crucial that this surplus weapons plutonium be managed in a way that minimizes the danger that it will be re-used for weapons,

Holdren

2009-01-01

117

Explosive properties of reactor?grade plutonium  

Microsoft Academic Search

The following discussion focuses on the question of whether a terrorist organization or a threshold state could make use of plutonium recovered from light?water?reactor fuel to construct a nuclear explosive device having a significantly damaging yield. Questions persist in some nonproliferation policy circles as to whether a bomb could be made from reactor?grade plutonium of high burn?up, and if so,

J. Carson Marka

1993-01-01

118

Guidelines for international plutonium management: Overview and implications  

SciTech Connect

In September, 1997, nine of the world`s plutonium-using countries agreed to a set of guidelines for international plutonium management, with acceptances to be submitted to the International Atomic Energy Agency on December 1. Following three years of discussion, the guidelines provide a unified package of accepted rules for the storage, handling, and transportation of civil plutonium as well as military plutonium that has been declared as no longer required for defense purposes. New requirements include a formal declaration of national plutonium strategies, which will recognize the environmental, economic, and proliferation concerns and the consequent importance of balancing plutonium supply and demand. Nations will also make annual declaration of their non-military stockpiles of unirradiated plutonium, together with estimates of the plutonium content in spent reactor fuel. These guidelines represent the first formally accepted recognition of the need for plutonium management of this scope and could thus provide a partial basis for future monitoring and policy regimes.

Bryson, M.C. [Los Alamos National Lab., NM (United States); Fitzgerald, C.P.; Kincaid, C. [Dept. of Energy, Washington, DC (United States)

1998-12-31

119

Plutonium Finishing Plant safety evaluation report  

SciTech Connect

The Plutonium Finishing Plant (PFP) previously known as the Plutonium Process and Storage Facility, or Z-Plant, was built and put into operation in 1949. Since 1949 PFP has been used for various processing missions, including plutonium purification, oxide production, metal production, parts fabrication, plutonium recovery, and the recovery of americium (Am-241). The PFP has also been used for receipt and large scale storage of plutonium scrap and product materials. The PFP Final Safety Analysis Report (FSAR) was prepared by WHC to document the hazards associated with the facility, present safety analyses of potential accident scenarios, and demonstrate the adequacy of safety class structures, systems, and components (SSCs) and operational safety requirements (OSRs) necessary to eliminate, control, or mitigate the identified hazards. Documented in this Safety Evaluation Report (SER) is DOE`s independent review and evaluation of the PFP FSAR and the basis for approval of the PFP FSAR. The evaluation is presented in a format that parallels the format of the PFP FSAR. As an aid to the reactor, a list of acronyms has been included at the beginning of this report. The DOE review concluded that the risks associated with conducting plutonium handling, processing, and storage operations within PFP facilities, as described in the PFP FSAR, are acceptable, since the accident safety analyses associated with these activities meet the WHC risk acceptance guidelines and DOE safety goals in SEN-35-91.

Not Available

1995-01-01

120

A vision for environmentally conscious plutonium processing  

SciTech Connect

Regardless of individual technical and political opinions about the uses of plutonium, it is virtually certain that plutonium processing will continue on a significant global scale for many decades for the purposes of national defense, nuclear power and remediation. An unavoidable aspect of plutonium processing is that radioactive contaminated gas, liquid, and solid streams are generated. These streams need to be handled in a manner that is not only in full compliance with today`s laws,but also will be considered environmentally and economically responsible now and in the future. In this regard, it is indeed ironic that the multibillion dollar and multidecade radioactive cleanup mortgage that the US Department of Energy (and its Russian counterpart) now owns resulted from waste management practices that were at the time in full legal compliance. The theme of this paper is that recent dramatic advances in actinide science and technology now make it possible to drastically minimize or even eliminate the problematic waste streams of traditional plutonium processing operations. Advanced technology thereby provides the means to avoid passing on to our children and grandchildren significant environmental and economic legacies that traditional processing inevitably produces. This paper will describe such a vision for plutonium processing that could be implemented fully within five years at a facility such as the Los Alamos Plutonium Facility (TA55). As a significant bonus, even on this short time scale, the initial technology investment is handsomely returned in avoided waste management costs.

Avens, L.R.; Eller, P.G.; Christensen, D.C. [Los Alamos National Lab., NM (United States). Nuclear Materials Technology Div.; Miller, W.L. [Univ. of Florida, Gainesville, FL (United States). Dept. of Environmental Engineering Sciences

1998-12-31

121

Characteristics of a Mixed Thorium - Uranium Dioxide High-Burnup Fuel  

SciTech Connect

Future nuclear fuel must satisfy three sets of requirements: longer times between refueling; concerns for weapons proliferation; and development of a spent fuel form more suitable for direct geologic disposal. This project has investigated a fuel consisting of mixed thorium and uranium dioxide to satisfy these requirements. Results using the SCALE 4.3 code system indicated that the mixed Th-U fuel could be burned to 72 MWD/kg or 100 MWD/kg using 25% and 35% UO2 respectively. The uranium remained below 20 % total fissile fraction throughout the cycle, making it unusable for weapons. Total plutonium production per MWD was a factor of 4.5 less in the Th-U fuel than in the conventional fuel; Pu-239 production per MWD was a factor of 6.5 less; and the plutonium produced was high in Pu-238, leading to a decay heat 5 times greater than that from plutonium derived from conventional fuel and 40 times greater than weapons grade plutonium. High decay heat would require active cooling of any crude weapon, lest the components surrounding the plutonium be melted. Spontaneous neutron production for plutonium from Th-U fuel was 2.3 times greater than that from conventional fuel and 15 times greater than that from weapons grade plutonium. High spontaneous neutron production drastically limits the probable yield of a crude weapon. Because ThO2 is the highest oxide of thorium, while UO2 can be oxidized further to U3O8, ThO2- UO2 fuel may be a superior wasteform if the spent fuel is ever to be exposed to oxygenated water. Even if the cost of fabricating the mixed Th-U fuel is $100/kg greater, the cost of the Th-U fuel is 13% to 25% less than that of the fuels using uranium only.

Herring, James Stephen; Mac Donald, Philip Elsworth

1999-06-01

122

Characteristics of a Mixed Thorium-Uranium Dioxide High-Burnup Fuel  

SciTech Connect

Future nuclear fuels must satisfy three sets of requirements: longer times between refueling; concerns for weapons proliferation; and development of a spent fuel form more suitable for direct geologic disposal. This project has investigated a fuel consisting of mixed thorium and uranium dioxide to satisfy these requirements. Results using the SCALE 4.3 code system indicated that the mixed Th-U fuel could be burned to 72 MWD/kg or 100 MWD/kg using 25% of 35% UO2 respectively. The uranium remained below 20% total fissile fraction throughout the cycle, making it unusable for weapons. Total plutonium production per MWD was a factor of 4.5 less in the Th-U fuel than in the conventional fuel; Pu-239 production per MWD was a factor of 6.5 less; and the plutonium produced was high in Pu-238, leading to a decay heat 5 times greater than that from plutonium derived from conventional fuel and 40 times greater than weapons grade plutonium. High decay heat would require active cooling of any crude weapon, lest the components surrounding the plutonium be melted. Spontaneous neutron production for plutonium from Th-U fuel was 2.3 times greater than that from conventional fuel and 15 times greater than that from weapons grade plutonium. High spontaneous neutron production drastically limits the probable yield of a crude weapon. Because ThO2 is the highest oxide of thorium, while UO2 can be oxidized further to U3O8, ThO2-UO2 fuel may be a superior wasteform if the spent fuel is ever to be exposed to oxygenated water. Even if the cost of fabricating the mixed Th-U fuel is $100/kg greater, the cost of the Th-U fuel is 13% to 15% less than that of the fuels using uranium only.

J. S. Herring; P. E. MacDonald

1999-06-01

123

Weapons-grade plutonium dispositioning. Volume 2: Comparison of plutonium disposition options  

Microsoft Academic Search

The Secretary of Energy requested the National Academy of Sciences (NAS) Committee on International Security and Arms Control to evaluate disposition options for weapons-grade plutonium. The Idaho National Engineering Laboratory (INEL) offered to assist the NAS in this evaluation by investigating the technical aspects of the disposition options and their capability for achieving plutonium annihilation levels greater than 90%. This

D. A. Brownson; D. J. Hanson; H. S. Blackman

1993-01-01

124

Recent trends of plutonium fallout observed in Japan: plutonium as a proxy for desertification.  

PubMed

Plutonium in monthly deposition samples collected in Tsukuba (the Meteorological Research Institute), Japan from 1990 to end of 2001 is reported, together with monthly plutonium deposition in Nagasaki and Yonaguni in 2000. The annual deposition of (239,240)Pu during the period from 1990 to 2001 shows no systematic interannual variation. However, monthly (239,240)Pu depositions show a typical seasonal variation with a maximum in spring season (March to April), which corresponds to seasonal cycle of soil dusts originating from the East Asian arid area. Plutonium isotopic ratios in the deposition samples suggest that significant amounts of the recent (239,240)Pu deposition observed in Japan are attributed to the resuspension of plutonium-bearing surface soil particles; resuspended plutonium originates from the East Asian arid areas. The recent increased tendency of (239,240)Pu content in residues in deposition samples may reflect desertification in the East Asian continent. PMID:12729272

Hirose, Katsumi; Igarashi, Yasuhito; Aoyama, Michio; Kim, C K; Kim, C S; Chang, B W

2003-04-01

125

Method for Plutonium-Gallium Separation by Anodic Dissolution of a Solid Plutonium-Gallium Alloy  

SciTech Connect

Purified plutonium and gallium are efficiently recovered from a solid plutonium-gallium (Pu-Ga) alloy by using an electrorefining process. The solid Pu-Ga alloy is the cell anode, preferably placed in a moving basket within the electrolyte. As the surface of the Pu-Ga anode is depleted in plutonium by the electrotransport of the plutonium to a cathode, the temperature of the electrolyte is sufficient to liquify the surface, preferably at about 500 C, resulting in a liquid anode layer substantially comprised of gallium. The gallium drips from the liquified surface and is collected below the anode within the electrochemical cell. The transported plutonium is collected on the cathode surface and is recovered.

Miller, William E.; Tomczuk, Zygmunt

1998-12-08

126

Preserving Plutonium-244 as a National Asset  

SciTech Connect

Plutonium-244 (244 Pu) is an extremely rare and long-lived isotope of plutonium with a half-life of 80 million years. Measureable amounts of 244 Pu are found in neither reactor-grade nor weapons-grade plutonium. Production of this isotope requires a very high thermal flux to permit the two successive neutron captures that convert 242 Pu to 243 Pu to 244 Pu, particularly given the short (about 5 hour) half-life of 243 Pu. Such conditions simply do not exist in plutonium production processes. Therefore, 244 Pu is ideal for precise radiochemical analyses measuring plutonium material properties and isotopic concentrations in items containing plutonium. Isotope dilution mass spectrometry is about ten times more sensitive when using 244 Pu rather than 242 Pu for determining plutonium isotopic content. The isotope can also be irradiated in small quantities to produce superheavy elements. The majority of the existing global inventory of 244 Pu is contained in the outer housing of Mark-18A targets at the Savannah River Site (SRS). The total inventory is about 20 grams of 244 Pu in about 400 grams of plutonium distributed among the 65 targets. Currently, there are no specific plans to preserve these targets. Although the cost of separating and preserving this material would be considerable, it is trivial in comparison to new production costs. For all practical purposes, the material is irreplaceable, because new production would cost billions of dollars and require a series of irradiation and chemical separation cycles spanning up to 50 years. This paper will discuss a set of options for overcoming the significant challenges to preserve the 244 Pu as a National Asset: (1) the need to relocate the material from SRS in a timely manner, (2) the need to reduce the volume of material to the extent possible for storage, and (3) the need to establish an operational capability to enrich the 244 Pu in significant quantities. This paper suggests that if all the Mark-18A plutonium is separated, it would occupy a small volume and would be inexpensive to store while an enrichment capability is developed. Very small quantities could be enriched in existing mass separators to support critical needs.

Patton, Bradley D [ORNL; Alexander, Charles W [ORNL; Benker, Dennis [ORNL; Collins, Emory D [ORNL; Romano, Catherine E [ORNL; Wham, Robert M [ORNL

2011-01-01

127

Effect of compositional variation in plutonium on process shielding design  

SciTech Connect

Radiation dose rate from plutonium with high {sup 239}Pu content varies with initial nuclidic content, radioactive decay time, and impurity elemental content. The two idealized states of old plutonium and clean plutonium, whose initial compositions are given, provide approximate upper and lower bounds on dose rate variation. Whole-body dose rates were calculated for the two composition states, using unshielded and shielded plutonium spheres of varying density. The dose rates from these variable density spheres are similar to those from expanded plutonium configurations encountered during processing. The dose location of 40 cm from the sphere center is representative of operator standoff for direct handling of plutonium inside a glove box. The results have shielding implications for glove boxes with only structurally inherent shielding, especially for processing of old plutonium in an expanded configuration. Further reduction in total dose rate by using lead to reduce photon dose rate is shown for two density cases representing compact and expanded plutonium configurations.

Brown, T.H.

1997-11-01

128

The plutonium-oxygen phase diagram  

SciTech Connect

Identification of products formed by the reaction of plutonium metal with liquid water at 23{degree}C indicates that the plutonium-oxygen phase diagram is similar to the cerium-oxygen and praseodymium-oxygen diagrams. Quantitative measurements of H{sub 2} formation and analytical data suggest that a sequence of hydrolysis reactions produces oxide hydrides of trivalent plutonium, Pu{sub 2}O{sub 3}, mixed-valent oxides and PuO{sub 2}. The intermediate oxides are the n {equals} 7, 9, 10 and 12 members of the Pu{sub n}O{sub 2n{minus}2} homologous series. Properties of the residue formed by thermal decomposition of the initial hydrolysis product, plutonium monoxide monhydride (PuOH), are consistent with the formation of metastable plutonium monoxide. Crystal-chemical, thermodynamic, and kinetic factors are evaluated, but definitive assignment of the equilibrium Pu-O diagram is not possible. 22 refs., 6 figs., 1 tab.

Haschke, J.M.

1990-01-01

129

Reactions of hexafluorides of uranium, neptunium, and plutonium with nitrogen oxides and oxyfluorides. Synthesis and characterization of (NO)[NpF 6] and (NO)[PuF 6  

Microsoft Academic Search

A comparative study has been performed of the reactions of nitric oxide (NO), nitrogen dioxide (NO2), nitrosyl fluoride (FNO), nitryl fluoride (FNO2), and nitrogen oxytrifluoride (F3NO) with the hexafluorides of uranium, neptunium, and plutonium. Significant chemical differences among the hexafluorides were found. Thus, UF6 and excess NO reacted at room temperature to form the nitrosonium salt (NO)[UF6], the same U(V)

P. Gary Eller; John G. Malm; Basil I. Swanson; Lester R. Morss

1998-01-01

130

PERSONAL MONITOR FOR NITROGEN DIOXIDE  

EPA Science Inventory

An attempt was made to develop a personal monitor to measure nitrogen dioxide. Sampling of nitrogen dioxide is accomplished by permeation through a silicone membrane into a alkaline thymol blue solution. The nitrogen dioxide is converted to nitrite and is then quantitated by colo...

131

8, 73157337, 2008 Carbon dioxide  

E-print Network

ACPD 8, 7315­7337, 2008 Carbon dioxide distributions over Europe C. Gurk et al. Title Page Abstract distributions of carbon dioxide over Europe C. Gurk1 , H. Fischer1 , P. Hoor1 , M.G. Lawrence1 , J. Lelieveld1 Publications on behalf of the European Geosciences Union. 7315 #12;ACPD 8, 7315­7337, 2008 Carbon dioxide

Paris-Sud XI, Université de

132

Arnold Schwarzenegger THE CARBON DIOXIDE  

E-print Network

i Arnold Schwarzenegger Governor THE CARBON DIOXIDE ABATEMENT POTENTIAL OF CALIFORNIA'S MID, Afzal Siddiqui, and Judy Lai. 2011. The Carbon Dioxide Abatement Potential of California's Mid/Agricultural/Water EndUse Energy Efficiency · Renewable Energy Technologies · Transportation The Carbon Dioxide

133

10 CFR 140.107 - Appendix G-Form of indemnity agreement with licensees processing plutonium for use in plutonium...  

Code of Federal Regulations, 2013 CFR

...licensees processing plutonium for use in plutonium processing and fuel fabrication plants and furnishing insurance policies...the agreement or is received at the plant for use or processing in the plant but which is, in fact, for any...

2013-01-01

134

10 CFR 140.108 - Appendix H-Form of indemnity agreement with licensees possessing plutonium for use in plutonium...  

Code of Federal Regulations, 2010 CFR

...licensees possessing plutonium for use in plutonium processing and fuel fabrication plants and furnishing proof of financial...the agreement or is received at the plant for use or processing in the plant but which is, in fact, for any...

2010-01-01

135

10 CFR 140.108 - Appendix H-Form of indemnity agreement with licensees possessing plutonium for use in plutonium...  

Code of Federal Regulations, 2011 CFR

...licensees possessing plutonium for use in plutonium processing and fuel fabrication plants and furnishing proof of financial...the agreement or is received at the plant for use or processing in the plant but which is, in fact, for any...

2011-01-01

136

10 CFR 140.107 - Appendix G-Form of indemnity agreement with licensees processing plutonium for use in plutonium...  

Code of Federal Regulations, 2010 CFR

...licensees processing plutonium for use in plutonium processing and fuel fabrication plants and furnishing insurance policies...the agreement or is received at the plant for use or processing in the plant but which is, in fact, for any...

2010-01-01

137

10 CFR 140.108 - Appendix H-Form of indemnity agreement with licensees possessing plutonium for use in plutonium...  

...licensees possessing plutonium for use in plutonium processing and fuel fabrication plants and furnishing proof of financial...the agreement or is received at the plant for use or processing in the plant but which is, in fact, for any...

2014-01-01

138

10 CFR 140.108 - Appendix H-Form of indemnity agreement with licensees possessing plutonium for use in plutonium...  

Code of Federal Regulations, 2013 CFR

...licensees possessing plutonium for use in plutonium processing and fuel fabrication plants and furnishing proof of financial...the agreement or is received at the plant for use or processing in the plant but which is, in fact, for any...

2013-01-01

139

10 CFR 140.108 - Appendix H-Form of indemnity agreement with licensees possessing plutonium for use in plutonium...  

Code of Federal Regulations, 2012 CFR

...licensees possessing plutonium for use in plutonium processing and fuel fabrication plants and furnishing proof of financial...the agreement or is received at the plant for use or processing in the plant but which is, in fact, for any...

2012-01-01

140

10 CFR 140.107 - Appendix G-Form of indemnity agreement with licensees processing plutonium for use in plutonium...  

...licensees processing plutonium for use in plutonium processing and fuel fabrication plants and furnishing insurance policies...the agreement or is received at the plant for use or processing in the plant but which is, in fact, for any...

2014-01-01

141

10 CFR 140.107 - Appendix G-Form of indemnity agreement with licensees processing plutonium for use in plutonium...  

Code of Federal Regulations, 2012 CFR

...licensees processing plutonium for use in plutonium processing and fuel fabrication plants and furnishing insurance policies...the agreement or is received at the plant for use or processing in the plant but which is, in fact, for any...

2012-01-01

142

10 CFR 140.107 - Appendix G-Form of indemnity agreement with licensees processing plutonium for use in plutonium...  

Code of Federal Regulations, 2011 CFR

...licensees processing plutonium for use in plutonium processing and fuel fabrication plants and furnishing insurance policies...the agreement or is received at the plant for use or processing in the plant but which is, in fact, for any...

2011-01-01

143

15. VIEW OF THE SAFE GEOMETRY PLUTONIUM METAL STORAGE PALLETS ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

15. VIEW OF THE SAFE GEOMETRY PLUTONIUM METAL STORAGE PALLETS FROM THE INSIDE OF AN INPUT-OUTPUT STATION. INDIVIDUAL CONTAINERS OF PLUTONIUM ARE STORED IN THE WATER-FILLED, DOUBLE-WALLED STAINLESS STEEL TUBES THAT ARE WELDED ONTO THE PALLETS. (12/3/88) - Rocky Flats Plant, Plutonium Recovery Facility, Northwest portion of Rocky Flats Plant, Golden, Jefferson County, CO

144

Plutonium in surface soil in the Hanford plant environs  

Microsoft Academic Search

Analyses for plutonium in air, water, and foodstuffs have long been part ; of the routine surveillance program at Hanford. In addition, the ground and ; other surfaces have been surveyed for plutonium where there was possible ; deposition from stack emissions, waste spills, etc., using direct instrument ; measurements. Detectable plutonium deposition from the few such incidents has ;

J. P. Corley; D. M. Robertson; F. P. Brauer

1972-01-01

145

Storage MOX: A Third Way for Plutonium Disposal?  

Microsoft Academic Search

By 2010, the UK could have 110 tons of separated civilian plutonium and Russia up to 150 tons of excess weapons and civil plutonium. Neither country has enough LWR capacity for disposal in MOX fuel. Plutonium disposal via MOX fuel is also difficult for some other countries. Combined disposal with HLW may be infeasible after reprocessing ends because the reprocessing

J. Kang; F. N. von Hippel; A. MacFarlane; R. Nelson

2002-01-01

146

The behaviour of plutonium in the Pacific Ocean  

Microsoft Academic Search

The Pacific Ocean is a major repository of plutonium released from atmospheric tests of nuclear weapons. Both global fallout from plutonium released to the stratosphere as well as close-in fallout from the troposphere contributed to the present levels of plutonium in seawater and sediment of the Pacific Ocean. The paper provides an overview of the state of knowledge of the

Hugh D. Livingston; Pavel P. Povinec; Toshimichi Ito; Orihiko Togawa

2001-01-01

147

Proceedings of the Plutonium Futures—The Science 2006 Conference  

Microsoft Academic Search

Plutonium Futures--The Science 2006 provided opportunities to examine present knowledge of the chemical and physical properties of plutonium and other actinides in complex media and materials; to discuss the current and emerging science (chemistry, physics, materials science, nuclear science, and environmental effects) of plutonium and actinides relevant to enhancing global nuclear security; and to exchange ideas. This international conference also

Michael J. Fluss; David E. Hobart; Patrick G. Allen; Gordon D. Jarvinen

2007-01-01

148

VIEW OF THE INTERIOR OF THE PLUTONIUM LABORATORY IN BUILDING ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

VIEW OF THE INTERIOR OF THE PLUTONIUM LABORATORY IN BUILDING 559. THE LABORATORY WAS USED TO ANALYZE THE PURITY OF PLUTONIUM. PLUTONIUM SAMPLES WERE CONTAINED WITHIN GLOVE BOXES - Rocky Flats Plant, Chemical Analytical Laboratory, North-central section of Plant, Golden, Jefferson County, CO

149

THE ROLE OF PLUTONIUM IN THE BRITISH NUCLEAR POWER PROGRAMME  

Microsoft Academic Search

There are two principal incentives for the utilization of plutonium in ; reactors as part of the British Nuclear Power Programme. Plutonium will become ; available in increasing amounts from the natural uranium reactors, and ; assessments indicate that fast reactors burning plutonium may produce power more ; cheaply than any other reactor systems so far envisaged. The nuclear ;

Kronberger

1963-01-01

150

Electrochemical investigation into the mechanism of plutonium reduction in electrorefining  

SciTech Connect

Currently impure plutonium metal is purified at Los Alamos National Laboratory by a molten salt electrorefining process. Electrorefining is an effective method for producing high-purity plutonium metal (> 99.95%). In general this process involves the oxidation of impure plutonium metal from a molten plutonium anode or a solvent metal/plutonium anode, transport of plutonium ions through a molten salt electrolyte, and reduction of the plutonium ions at a tungsten cathode to pure plutonium metal. Purification of the plutonium metal from impurities is based on the difference in free energies of formation between the various metallic impurities associated with plutonium. To obtain a better understanding of the overall electrorefining process and its inefficiencies, an electrochemical investigation into the mechanism for plutonium reduction in a typical electrorefining environment was undertaken. Cyclic voltammetry was selected as the method for determining the electrode mechanism for plutonium reduction at tungsten electrodes. In addition to the standard electrorefining melt (equimolar NaCl-KCl), additional melts that were being investigated in our solvent anode work were also investigated. With insight gained from this investigation, it was hoped that a better selection of electrorefining operating parameters could be obtained.

McCurry, L.E.; Moy, G.M.M.

1987-01-01

151

Preparation of a glovebox for casting enriched plutonium.  

SciTech Connect

Objectives: Prepare existing glovebox for casting, heat treating and storing enriched plutonium, Upgrade seismic systems to reduce dispersion hazard, Upgrade atmospheric systems to reduce oxidation of plutonium, Upgrade vacuum system to prevent oxidation, InstalI/upgrade induction heating systems to melt plutonium and heat mold

Ronquillo, R. D. (Richard D.); Trujillo, C. M. (Chris M.); Trujillo, C. C. (Claudette C.)

2002-01-01

152

Method for dissolving delta-phase plutonium  

SciTech Connect

A process for dissolving plutonium, and in particular, delta-phase plutonium. The process includes heating a mixture of nitric acid, hydroxylammonium nitrate and potassium fluoride (HAN) to a temperature between 40 and 70 C, then immersing the metal in the mixture. Preferably, the nitric acid has a concentration of not ore than 2M, the HAN approximately 0.66M, and the potassium fluoride 1M. Additionally, a small amount of sulfamic acid, such as 0.1M can be added to assure stability of the HAN in the presence of nitric acid. The oxide layer that forms on plutonium metal may be removed with a non-oxidizing acid as a pre-treatment step.

Karraker, D.G.

1992-12-31

153

Excess plutonium disposition: The deep borehole option  

SciTech Connect

This report reviews the current status of technologies required for the disposition of plutonium in Very Deep Holes (VDH). It is in response to a recent National Academy of Sciences (NAS) report which addressed the management of excess weapons plutonium and recommended three approaches to the ultimate disposition of excess plutonium: (1) fabrication and use as a fuel in existing or modified reactors in a once-through cycle, (2) vitrification with high-level radioactive waste for repository disposition, (3) burial in deep boreholes. As indicated in the NAS report, substantial effort would be required to address the broad range of issues related to deep bore-hole emplacement. Subjects reviewed in this report include geology and hydrology, design and engineering, safety and licensing, policy decisions that can impact the viability of the concept, and applicable international programs. Key technical areas that would require attention should decisions be made to further develop the borehole emplacement option are identified.

Ferguson, K.L.

1994-08-09

154

Method for dissolving delta-phase plutonium  

DOEpatents

A process for dissolving plutonium, and in particular, delta-phase plutonium. The process includes heating a mixture of nitric acid, hydroxylammonium nitrate (HAN) and potassium fluoride to a temperature between 40.degree. and 70.degree. C., then immersing the metal in the mixture. Preferably, the nitric acid has a concentration of not more than 2M, the HAN approximately 0.66M, and the potassium fluoride 0.1M. Additionally, a small amount of sulfamic acid, such as 0.1M can be added to assure stability of the HAN in the presence of nitric acid. The oxide layer that forms on plutonium metal may be removed with a non-oxidizing acid as a pre-treatment step.

Karraker, David G. (1600 Sherwood Pl., SE., Aiken, SC 29801)

1992-01-01

155

Atmospheric Carbon Dioxide  

NSDL National Science Digital Library

This figure, the famous Keeling Curve, shows the history of atmospheric carbon dioxide concentrations as directly measured at Mauna Loa, Hawaii. This curve is an essential piece of evidence that shows the increased greenhouse gases that cause recent increases in global temperatures.

Rohde, Robert A.; (from published NOAA data)

156

Bench Remarks: Carbon Dioxide.  

ERIC Educational Resources Information Center

Discusses the properties of carbon dioxide in its solid "dry ice" stage. Suggests several demonstrations and experiments that use dry ice to illustrate Avogadro's Law, Boyle's Law, Kinetic-Molecular Theory, and the effects of dry ice in basic solution, in limewater, and in acetone. (TW)

Bent, Henry A.

1987-01-01

157

Carbon Dioxide Laser Guidelines  

PubMed Central

The carbon dioxide (CO2) laser is a versatile tool that has applications in ablative lasing and caters to the needs of routine dermatological practice as well as the aesthetic, cosmetic and rejuvenation segments. This article details the basics of the laser physics as applicable to the CO2 laser and offers guidelines for use in many of the above indications. PMID:20808594

Krupa Shankar, DS; Chakravarthi, M; Shilpakar, Rachana

2009-01-01

158

Sulfur Dioxide Pollution Monitor.  

ERIC Educational Resources Information Center

The sulfur dioxide pollution monitor described in this document is a government-owed invention that is available for licensing. The background of the invention is outlined, and drawings of the monitor together with a detailed description of its function are provided. A sample stream of air, smokestack gas or the like is flowed through a…

National Bureau of Standards (DOC), Washington, DC.

159

Carbon Dioxide Removal  

NSDL National Science Digital Library

In this experiment using sprigs of Elodea, learners will observe a natural process that removes carbon dioxide (CO2) from Earth's atmosphere. This process is a part of the carbon cycle and results in temperature suitable for life. Note: this experiment requires that learners make observations an hour or the next day after they set up the materials.

History, American M.

2008-01-01

160

A vision for environmentally conscious plutonium processing  

SciTech Connect

Regardless of individual technical and political opinions about the uses of plutonium, it is virtually certain that plutonium processing will continue on a significant global scale for many decades for the purposes of national defense, nuclear power, and remediation. An unavoidable aspect of plutonium processing is that radioactively contaminated gas, liquid, and solid waste streams are generated. These streams need to be handled in a manner that not only is in full compliance with today`s laws but also will be considered environmentally and economically responsible now and in the future. In this regard, it is indeed ironic that the multibillion dollar and multidecade radioactive cleanup mortgage that the US Department of Energy (and its Russian counterpart) now owns resulted from waste management practices that were at the time in full legal compliance. It is now abundantly evident that in the long run, these practices have proven to be neither environmentally nor economically sound. Recent dramatic advances in actinide science and technology now make it possible to drastically minimize or even eliminate the problematic waste streams of traditional plutonium processing operations. Advanced technology thereby provides the means to avoid passing on to children and grandchildren significant environmental and economic legacies that traditional processing inevitably produces. The authors describe such a vision for plutonium processing that could be implemented fully within 5 yr at a facility such as the Los Alamos National Laboratory Plutonium Facility (TA55). As a significant bonus, even on this short timescale, the initial technology investment is handsomely returned in avoided waste management costs.

Avens, L.R.; Eller, P.G.; Christensen, D.C. [Los Alamos National Lab., NM (United States); Miller, W.L. [Univ. of Florida, Gainesville, FL (United States)

1998-12-31

161

Closure Welding of Plutonium Bearing Storage Containers  

SciTech Connect

A key element in the Department of Energy (DOE) strategy for the stabilization, packaging and storage of plutonium-bearing materials involves closure welding of DOE-STD-3013 Outer Containers (3013 container). The 3013 container provides the primary barrier and pressure boundary preventing release of plutonium-bearing materials to the environment. The final closure (closure weld) of the 3013 container must be leaktight, structurally sound and meet DOE STD 3013 specified criteria. This paper focuses on the development, qualification and demonstration of the welding process for the closure welding of Hanford PFP 3013 outer containers.

Cannell, G.R.

2002-02-28

162

Solubility of plutonium from rumen contents of cattle grazing on plutonium- contaminated desert vegetation in in vitro bovine gastrointestinal fluids  

Microsoft Academic Search

Rumen contents of cattle grazing on plutonium-contaminated desert ; vegetation at the Nevada Test Site were incubated in simulated bovine ; gastrointestinal fluids to study the alimentary solubility of plutonium. Trials ; were run during November 1973, and during February, May, July and August 1974. ; During the May and July trials, a large increase in plutonium solubility ; accompanied

J. Barth; M. G. White; P. B. Dunaway

1975-01-01

163

Modeling of Diffusion of Plutonium in Other Metals and of Gaseous Species in Plutonium-Based Systems  

SciTech Connect

Establish standards for temperature conditions under which plutonium, uranium, or neptunium from nuclear wastes permeates steel, with which it is in contact, by diffusion processes. The primary focus is on plutonium because of the greater difficulties created by the peculiarities of face-centered-cubic-stabilized (delta) plutonium (the form used in the technology generating the waste).

Bernard R. Cooper; Gayanath W. Fernando; S. Beiden; A. Setty; E.H. Sevilla

2004-07-02

164

Determination of plutonium-239 + plutonium-240 and plutonium-241 in environmental samples using low-level liquid scintillation spectrometry.  

PubMed

A radiochemical method for the simultaneous determination of 239Pu + 240Pu and 241Pu in environmental samples has been developed. In the course of the analysis a 236Pu tracer was used for estimating the chemical yield of plutonium isotopes. After suitable pre-treatment of the sample, the plutonium nuclides in solution were coprecipitated with iron(III) hydroxide and calcium oxalate and isolated further from impurities and interfering radionuclides by means of anion-exchange chromatography. Plutonium isotopes in the eluate (NH4I-HCI) were converted into nitrate form and then extracted with 20 ml of 5% bis(2-ethylhexyl) hydrogen phosphate extractive cocktail. The final organic solution was measured spectrometrically using an ultra-low-level liquid scintillation spectrometer, Quantulus (LKB, 1220 Wallac). The chemical yields of plutonium range from 25 to 50% for 100 I of sea-water and 30 to 60% for 40 g of dried soil sample. The counting efficiencies are nearly 100% for 239Pu + 240Pu and 48.8% for 241Pu, respectively. The detection limits were estimated to be 0.20 mBq for 239Pu + 240Pu and 2.2 mBq for 241Pu, respectively. The proposed procedure has been tested for the simultaneous determination of 239Pu + 240Pu and 241Pu in sea-water (Irish Sea, North Sea) and soils (Cumbrian coast, UK; Byelorussia, USSR). PMID:1580376

Yu, Y F; Bjørnstad, H E; Salbu, B

1992-03-01

165

IAEA activities on the safe handling and disposition of plutonium  

SciTech Connect

The buildup of the inventory of plutonium from dismantled warheads as well as from civilian nuclear programs and its disposition are under intense international debate. The activities of the IAEA in the technical area will be presented in this paper. It deals with (1) estimation of world wide inventories of civil plutonium both current and projected, (2) preparation of a safety document on safe handling and storage of plutonium, (3) exchange of information and discussion on some reactor technologies associated with the disposition of plutonium and it provides the necessary support to the ongoing initiatives for more transparency in management of plutonium.

Oi, N. [International Atomic Energy Agency, Vienna (Austria). Division of Nuclear Fuel Cycle and Waste Management

1995-12-31

166

Plutonium dispersal in fires: Summary of what is known  

SciTech Connect

In view of the great public apprehension about plutonium and nuclear weapons we should explore ways to prevent, limit, or mitigate possible plutonium dispersals. This review is primarily a tutorial on what is known about plutonium dispersal in fires. It concludes that in most types of fires involving plutonium the amount released will not be an immediate danger to life. Indeed, in many cases very few personnel will receive more than the lung burden allowed by current regulations for plutonium workers. However, the dangers may be significant in special situations, unusual terrains, certain meteorological conditions, and very high burn temperatures.

Condit, R.H.

1993-07-01

167

Six-kilogram-scale electrorefining of plutonium metal  

SciTech Connect

The electrorefining of metallic plutonium scrap to produce high purity metal has been an established procedure at Los Alamos since 1964. This is a batch process and was limited to 4-kg plutonium because of criticality safety considerations. Improvements in critical mass measurements have permitted us to develop a process for 6-kg plutonium. The 6-kg process is now operational. The increased size of the process, together with other improvements which have been made, makes plutonium electrorefining the principal industrial tool for processing and purifying metallic plutonium scrap.

Mullins, L.J.; Morgan, A.N.; Apgar, S.A. III; Christensen, D.C.

1982-09-01

168

Gas-phase energies of actinide oxides -- an assessment of neutral and cationic monoxides and dioxides from thorium to curium  

SciTech Connect

An assessment of the gas-phase energetics of neutral and singly and doubly charged cationic actinide monoxides and dioxides of thorium, protactinium, uranium, neptunium, plutonium, americium, and curium is presented. A consistent set of metal-oxygen bond dissociation enthalpies, ionization energies, and enthalpies of formation, including new or revised values, is proposed, mainly based on recent experimental data and on correlations with the electronic energetics of the atoms or cations and with condensed-phase thermochemistry.

Marcalo, Joaquim; Gibson, John K.

2009-08-10

169

PROSERPINE. HOMOGENEOUS CRITICAL EXPERIMENT WITH PLUTONIUM  

Microsoft Academic Search

The Proserpine, a zero power homogeneous reactor experiment with ; plutonium sulfate dissolved in light water, is briefly described. The lowest ; critical mass is 257.2 g of Pu. The vessel is of Zircaloy surrounded by a ; reflector of beryllium oxide. The absolute calibration of reactivlty by ; poisoning with boron and the study of the temperature coefficient in

Tachon

1958-01-01

170

Electrochemically Modulated Separation for Plutonium Safeguards  

SciTech Connect

Accurate and timely analysis of plutonium in spent nuclear fuel is critical in nuclear safeguards for detection of both protracted and rapid plutonium diversions. Gamma spectroscopy is a viable method for accurate and timely measurements of plutonium provided that the plutonium is well separated from the interfering fission and activation products present in spent nuclear fuel. Electrochemically modulated separation (EMS) is a method that has been used successfully to isolate picogram amounts of Pu from nitric acid matrices. With EMS, Pu adsorption may be turned "on" and "off" depending on the applied voltage, allowing for collection and stripping of Pu without the addition of chemical reagents. In this work, we have scaled up the EMS process to isolate microgram quantities of Pu from matrices encountered in spent nuclear fuel during reprocessing. Several challenges have been addressed including surface area limitations, radiolysis effects, electrochemical cell performance stability, and chemical interferences. After these challenges were resolved, 6 µg Pu was deposited in the electrochemical cell with approximately an 800-fold reduction of fission and activation product levels from a spent nuclear fuel sample. Modeling showed that these levels of Pu collection and interference reduction may not be sufficient for Pu detection by gamma spectroscopy. The main remaining challenges are to achieve a more complete Pu isolation and to deposit larger quantities of Pu for successful gamma analysis of Pu. If gamma analyses of Pu are successful, EMS will allow for accurate and timely on-site analysis for enhanced Pu safeguards.

Pratt, Sandra H.; Breshears, Andrew T.; Arrigo, Leah M.; Schwantes, Jon M.; Duckworth, Douglas C.

2013-12-31

171

Plutonium Immobilization Can Loading Equipment Review  

SciTech Connect

This report lists the operations required to complete the Can Loading steps on the Pu Immobilization Plant Flow Sheets and evaluates the equipment options to complete each operation. This report recommends the most appropriate equipment to support Plutonium Immobilization Can Loading operations.

Kriikku, E. [Westinghouse Savannah River Company, AIKEN, SC (United States); Ward, C.; Stokes, M.; Randall, B.; Steed, J.; Jones, R.; Hamilton, L.

1998-05-01

172

Proliferation Resistance Attributes of Advanced Plutonium Processing  

Microsoft Academic Search

To obtain public acceptance for future use of Pu, new concepts must overcome the present concerns about environmental compliance as well as con- cerns about misusing plutonium of the civil nuclear fuel cycle for nuclear explosives e.g. by terrorists. In future the preferable remedy is the multi-recycling of all transuranium elements in fast neutron reac- tors. In such a partitioning

L. Koch

173

Plutonium fractionation in southern Baltic Sea sediments  

Microsoft Academic Search

In this study, different chemical plutonium fractions (dissolved in water, connected to carbonates, connected to oxides, complexed with organic matter, mineral acids soluble and the rest) in sediments from the Vistula River estuary, the Gda?sk Basin and the Bornholm Deep were determined. The distribution of Pu in analysed sediments samples was not uniform but dependent on its chemical form, depth

Dagmara I. Strumi?ska-Parulska; Bogdan Skwarzec; Magdalena Pawlukowska

2012-01-01

174

Plutonium Management in the Medium Term  

SciTech Connect

For many years various countries with access to commercial reprocessing services have been routinely recycling plutonium as UO{sub 2}/PuO{sub 2} mixed oxide (MOX) fuel in light water reactors (LWRs). This LWR MOX recycle strategy is still widely regarded as an interim step leading to the eventual establishment of sustainable fast reactor fuel cycles. The OECD/NEA Working Party on the Physics of Plutonium Fuels and Innovative Fuel Cycles (WPPR) has recently completed a review of the technical options for plutonium management in what it refers to as the 'medium term'. For the purpose of the review, the WPPR considers the medium term to cover the period from now up to the point at which fast reactor fuel cycles are established on a commercial scale. The review identified a number of different designs of innovative plutonium fuel assemblies intended to be used in current LWR cores, in LWRs with significantly different moderation properties, as well as in high-temperature gas reactors. The full review report describes these various options and highlights their respective advantages and disadvantages. This paper briefly summarizes the main findings of the review.

Hesketh, Kevin [BNFL Nuclear Sciences and Technology Services (United Kingdom); Schlosser, Gerhard; Porsch, Dieter F. [Framatome ANP (France); Wolf, Timm [Framatome ANP (France); Koeberl, Oliver [CEA Cadarache (France); Lance, Benoit [Belgonucleaire (Belgium); Chawla, Rakesh [Paul Scherrer Institut (Switzerland); Gehin, Jess C. [Oak Ridge National Laboratory (United States); Ellis, Ron [Oak Ridge National Laboratory (United States); Uchikawa, Sadao [Japan Atomic Energy Research Institute (Japan); Sato, Osamu [Japan Atomic Energy Research Institute (Japan); Okubo, Tsutomu [Japan Atomic Energy Research Institute (Japan); Mineo, Hideaki [Japan Atomic Energy Research Institute (Japan); Yamamoto, Toru [Nuclear Power Engineering Corporation (Japan); Sagayama, Yutaka [Japan Nuclear Cycle Development Institute (Japan); Sartori, Enrico [Organization for Economic Cooperation and Development (France)

2004-12-15

175

Modeling Carbon Dioxide Levels  

NSDL National Science Digital Library

In this activity students will explore levels of Carbon Dioxide ( C02) in the atmosphere over time. There is concern that levels of C02 are rising; and finding a good mathematical model for CO2 levels is an important part of determining if this is attributable to human technology. Students draw a scatter plot, choose two points to create a linear model for the data, then use the model to make predictions.

2009-01-01

176

Sulfur dioxide removal process  

Microsoft Academic Search

A process is described for reducing the loss of sodium values in a system for removing sulfur dioxide from a gas by the use of an absorption-desorption cycle employing aqueous sodium sulfite as the essential absorption solution. Sodium sulfate and\\/or sodium thio-sulfate build-up in the system is avoided and the loss of sodium values reduced by subjecting sodium sulfate and\\/or

N. E. Nicholson; J. Scarlett

1978-01-01

177

CARBON DIOXIDE FIXATION.  

SciTech Connect

Solar carbon dioxide fixation offers the possibility of a renewable source of chemicals and fuels in the future. Its realization rests on future advances in the efficiency of solar energy collection and development of suitable catalysts for CO{sub 2} conversion. Recent achievements in the efficiency of solar energy conversion and in catalysis suggest that this approach holds a great deal of promise for contributing to future needs for fuels and chemicals.

FUJITA,E.

2000-01-12

178

Titanium dioxide photocatalysis  

Microsoft Academic Search

Scientific studies on photocatalysis started about two and a half decades ago. Titanium dioxide (TiO2), which is one of the most basic materials in our daily life, has emerged as an excellent photocatalyst material for environmental purification. In this review, current progress in the area of TiO2 photocatalysis, mainly photocatalytic air purification, sterilization and cancer therapy are discussed together with

Akira Fujishima; Tata N. Rao; Donald A. Tryk

2000-01-01

179

Plutonium in the air in Kurchatov, Kazakhstan.  

PubMed

Weekly air samples of 25000 m(3) volume were taken with two air samplers over a period of one year in 2000-2001 in the town of Kurchatov in Kazakhstan. For another three-month period in 2001, the samplers were run in the city of Astana, about 500 km west of Kurchatov. (137)Cs, Pu and U concentrations were determined from the filters. Pu activities in Kurchatov varied in a 100-fold range; median (239,240)Pu activities were 100 nBq/m(3) and (238)Pu activities 34 nBq/m(3). The corresponding values for Astana were considerably lower: 29 and 9 nBq/m(3), respectively, and in half of the filters the (238)Pu activity was below the detection limit. Plutonium concentration correlated with the amount of dust retained on the filters only at the highest dust loads. Also no correlation between wind speed and the plutonium activity in the filters was observed. Thus, resuspension does not seem to be the mechanism responsible for the airborne plutonium. No clear seasonal variation of Pu air concentration was observed, though levels were somewhat elevated in February to April. There was no correlation between the plutonium and (137)Cs concentrations. In most of the filters the cesium concentration was below the detection limit, but in those filters where it could be detected the cesium concentration was practically constant at 3.9+/-1.6 microBq/m(3). Dose estimation for the inhalation of the airborne plutonium gave a low value of 0.018 microSv/a for the inhabitants in Kurchatov, which is about a thousand times lower than the dose caused by the naturally occurring (210)Po. Air parcel trajectory analysis indicated that the observed Pu activities in the air could not unambiguously be attributed to the most contaminated areas at the Semipalatinsk Test Site. PMID:16197982

Lehto, J; Salminen, S; Jaakkola, T; Outola, I; Pulli, S; Paatero, J; Tarvainen, M; Ristonmaa, S; Zilliacus, R; Ossintsev, A; Larin, V

2006-07-31

180

In search of plutonium: A nonproliferation journey  

NASA Astrophysics Data System (ADS)

In February 1992, I landed in the formerly secret city of Sarov, the Russian Los Alamos, followed a few days later by a visit to Snezhinsk, their Livermore. The briefings we received of the Russian nuclear weapons program and tours of their plutonium, reactor, explosives, and laser facilities were mind boggling considering the Soviet Union was dissolved only two months earlier. This visit began a 17-year, 41 journey relationship with the Russian nuclear complex dedicated to working with them in partnership to protect and safeguard their weapons and fissile materials, while addressing the plight of their scientists and engineers. In the process, we solved a forty-year disagreement about the plutonium-gallium phase diagram and began a series of fundamental plutonium science workshops that are now in their tenth year. At the Yonbyon reprocessing facility in January 2004, my North Korean hosts had hoped to convince me that they have a nuclear deterrent. When I expressed skepticism, they asked if I wanted to see their ``product.'' I asked if they meant the plutonium; they replied, ``Well, yes.'' Thus, I wound up holding 200 grams of North Korean plutonium (in a sealed glass jar) to make sure it was heavy and warm. So began the first of my six journeys to North Korea to provide technical input to the continuing North Korean nuclear puzzle. In Trombay and Kalpakkam a few years later I visited the Indian nuclear research centers to try to understand how India's ambitious plans for nuclear power expansion can be accomplished safely and securely. I will describe these and other attempts to deal with the nonproliferation legacy of the cold war and the new challenges ahead. )

Hecker, Siegfried

2010-02-01

181

Plutonium contamination in the environment. (Latest citations from Pollution abstracts). Published Search  

SciTech Connect

The bibliography contains citations concerning the ecological impact of plutonium contamination in the environment. Topics include plutonium contamination in freshwater and marine sediments, plutonium bioaccumulation, plutonium transport in the food chain, plutonium accumulation in the soil, methods of analysis, plutonium removal from contaminated soils, and plutonium contamination from nuclear fallout and nuclear waste. Government regulations on containment and disposal of plutonium contaminated wastes are described. Government regulations regarding plutonium levels in consumer products and drinking water are discussed. (Contains a minimum of 208 citations and includes a subject term index and title list.)

Not Available

1993-05-01

182

A Note on the Reaction of Hydrogen and Plutonium  

SciTech Connect

Plutonium hydride has many practical and experimental purposes. The reaction of plutonium and hydrogen has interesting characteristics, which will be explored in the following analysis. Plutonium is a radioactive actinide metal that emits alpha particles. When plutonium metal is exposed to air, the plutonium oxides and hydrides, and the volume increases. PuH{sub 2} and Pu{sub 2}O{sub 3} are the products. Hydrogen is a catalyst for plutonium's corrosion in air. The reaction can take place at room temperature because it is fairly insensitive to temperature. Plutonium hydride, or PuH{sub 2}, is black and metallic. After PuH{sub 2} is formed, it quickly flakes off and burns. The reaction of hydrogen and plutonium is described as pyrophoric because the product will spontaneously ignite when oxygen is present. This tendency must be considered in the storage of metal plutonium. The reaction is characterized as reversible and nonstoichiometric. The reaction goes as such: Pu + H{sub 2} {yields} PuH{sub 2}. When PuH{sub 2} is formed, the hydrogen/plutonium ratio is between 2 and 2.75 (approximately). As more hydrogen is added to the system, the ratio increases. When the ratio exceeds 2.75, PuH{sub 3} begins to form along with PuH{sub 2}. Once the ratio surpasses 2.9, only PuH{sub 3} remains. The volume of the plutonium sample increases because of the added hydrogen and the change in crystal structure which the sample undergoes. As more hydrogen is added to a system of metal plutonium, the crystal structure evolves. Plutonium has a crystal structure classified as monoclinic. A monoclinic crystal structure appears to be a rectangular prism. When plutonium reacts with hydrogen, the product PuH{sub 2}, becomes a fluorite structure. It can also be described as a face centered cubic structure. PuH{sub 3} forms a hexagonal crystal structure. As plutonium evolves from metal plutonium to plutonium hydride to plutonium trihydride, the crystal structure evolves from monoclinic to fluorite to hexagonal. This change in crystal structure as a result of adding hydrogen is a shared characteristic with other actinide elements. Americium is isostructural with plutonium because they both form cubic dihyrides and hexagonal trihydrides. Reacting hydrogen with plutonium has the practical application of separating plutonium from other materials that don't react as well with hydrogen. When plutonium is placed in a chamber where there is very little oxygen, it can react with hydrogen without igniting. The hydrogen plutonium reaction can then be reversed, thus regaining the separated plutonium. Another application of this reaction is that it can be used to predict how plutonium reacts with other substances. Deuterium and tritium are two isotopes of hydrogen that are of interest. They are known to react likewise to hydrogen because they have similar properties. The reaction of plutonium and isotopes of hydrogen can prove to be very informative.

Noone, Bailey C [Los Alamos National Laboratory

2012-08-15

183

Resuspension studies at Bikini Atoll. [Pulmonary exposure from dust-borne plutonium aerosols  

Microsoft Academic Search

The following experiments were conducted on Bikini Atoll to provide key parameters for an assessment of inhalation exposure from plutonium-contaminated dust aerosols: (1) a characterization of background (plutonium activity, dust, plutonium, sea spray, and organic aerosol concentrations); (2) a study of plutonium resuspension from a bare field; (3) a study of plutonium resuspension by traffic; and (4) a study of

J. H. Shinn; D. N. Homan; W. L. Robison

1980-01-01

184

Introduction Air Quality and Nitrogen Dioxide  

E-print Network

Introduction Air Quality and Nitrogen Dioxide Air pollution can be defined as "the presence worldwide" WHO Air quality guidelines for particulate matter, ozone, nitrogen dioxide and sulphur dioxide and motor vehicles. Nitrogen Dioxide is produced in a number of combustion processes. Nitrogen dioxide can

185

Carbon dioxide affects global ecology  

Microsoft Academic Search

Man's activities are changing the carbon dioxide and oxygen content of the entire atmosphere. These changes may, in turn, affect worldwide weather and the growth of plants. Under normal conditions, the amounts of carbon dioxide and oxygen in the atmosphere remain approximately in equilibrium on a year-to-year basis. The atmosphere today contains about 21% oxygen and about 0.032% carbon dioxide

Eugene K. Peterson

1969-01-01

186

Plutonium disposition via immobilization in ceramic or glass  

SciTech Connect

The management of surplus weapons plutonium is an important and urgent task with profound environmental, national, and international security implications. In the aftermath of the Cold War, Presidential Policy Directive 13, and various analyses by renown scientific, technical, and international policy organizations have brought about a focused effort within the Department of Energy to identify and implement paths for the long term disposition of surplus weapons- usable plutonium. The central goal of this effort is to render surplus weapons plutonium as inaccessible and unattractive for reuse in nuclear weapons as the much larger and growing stock of plutonium contained in spent fuel from civilian reactors. One disposition option being considered for surplus plutonium is immobilization, in which the plutonium would be incorporated into a glass or ceramic material that would ultimately be entombed permanently in a geologic repository for high-level waste.

Gray, L.W.; Kan, T.; Shaw, H.F.; Armantrout, A.

1997-03-05

187

Los Alamos Plutonium Facility Waste Management System  

SciTech Connect

This paper describes the new computer-based transuranic (TRU) Waste Management System (WMS) being implemented at the Plutonium Facility at Los Alamos National Laboratory (LANL). The Waste Management System is a distributed computer processing system stored in a Sybase database and accessed by a graphical user interface (GUI) written in Omnis7. It resides on the local area network at the Plutonium Facility and is accessible by authorized TRU waste originators, count room personnel, radiation protection technicians (RPTs), quality assurance personnel, and waste management personnel for data input and verification. Future goals include bringing outside groups like the LANL Waste Management Facility on-line to participate in this streamlined system. The WMS is changing the TRU paper trail into a computer trail, saving time and eliminating errors and inconsistencies in the process.

Smith, K.; Montoya, A.; Wieneke, R.; Wulff, D.; Smith, C.; Gruetzmacher, K.

1997-02-01

188

Purification of plutonium via electromagnetic levitation  

NASA Astrophysics Data System (ADS)

Plutonium metal that has been double electrorefined (ER) was further purified via zone refining, using a levitated molten zone to minimize the introduction of impurities. The temperature of the molten zone was 750 °C, and the atmosphere was 10-5 Pa. A total of ten zone refining passes were made at a travel rate of 1.5 cm/hr. In order to study the efficiency of the zone refining process, core samples were taken after every two zone refining passes in five locations along the length plutonium specimen. Several impurities were reduced to levels below that of instrument detection limits, and it appears that six sequential zone refining passes are required to obtain the highest purity metal.

Lashley, J. C.; Blau, M. S.; Quagliano, J. R.

2000-07-01

189

Spectroscopy of plutonium-organic complexes  

SciTech Connect

Information on the spectroscopy of plutonium-organic complexes is needed to help establish the speciation of these complexes under environmentally relevant conditions. Laser photoacoustic spectroscopy (LPAS) and absorption spectrometry were used to characterize the Pu(IV)-citrate and Pu(IV)-nitrilotriacetic acid (NTA) complexes at concentrations of 10{sup {minus}3}--10{sup {minus}7} M in aqueous solution. Good agreement was observed between the band shape of the LPAS and absorption spectra for the Pu(IV)-NTA complex. Agreement for the Pu(IV)-citrate complex was not quite as good. In both cases, a linear dependence of the LPAS signal on laser power and total concentration of the complexes was noted. This work is part of an ongoing research effort to study key subsurface interactions of plutonium-organic complexes.

Richmann, M.K.; Reed, D.T.

1995-12-31

190

21 CFR 73.575 - Titanium dioxide.  

...2) Color additive mixtures for food use made with titanium dioxide...in color additive mixtures for coloring foods, and the following: Silicon dioxide...dioxide may be safely used for coloring foods generally, subject to the...

2014-04-01

191

21 CFR 73.575 - Titanium dioxide.  

Code of Federal Regulations, 2012 CFR

...2) Color additive mixtures for food use made with titanium dioxide...in color additive mixtures for coloring foods, and the following: Silicon dioxide...dioxide may be safely used for coloring foods generally, subject to the...

2012-04-01

192

21 CFR 73.575 - Titanium dioxide.  

Code of Federal Regulations, 2013 CFR

...2) Color additive mixtures for food use made with titanium dioxide...in color additive mixtures for coloring foods, and the following: Silicon dioxide...dioxide may be safely used for coloring foods generally, subject to the...

2013-04-01

193

21 CFR 73.3126 - Titanium dioxide.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Titanium dioxide. 73.3126 Section 73... Medical Devices § 73.3126 Titanium dioxide. (a) Identity and specifications. The color additive titanium dioxide (CAS Reg. No....

2010-04-01

194

21 CFR 73.1575 - Titanium dioxide.  

Code of Federal Regulations, 2012 CFR

... 2012-04-01 false Titanium dioxide. 73.1575 Section 73.1575...CERTIFICATION Drugs § 73.1575 Titanium dioxide. (a) Identity and specifications. (1) The color additive titanium dioxide shall conform in identity and...

2012-04-01

195

21 CFR 172.480 - Silicon dioxide.  

...2014-04-01 2014-04-01 false Silicon dioxide. 172.480 Section 172.480 Food and... Anticaking Agents § 172.480 Silicon dioxide. The food additive silicon dioxide may be safely used in food in accordance...

2014-04-01

196

21 CFR 172.480 - Silicon dioxide.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Silicon dioxide. 172.480 Section 172.480 Food and... Anticaking Agents § 172.480 Silicon dioxide. The food additive silicon dioxide may be safely used in food in accordance...

2011-04-01

197

21 CFR 73.2575 - Titanium dioxide.  

... 2014-04-01 false Titanium dioxide. 73.2575 Section 73.2575... Cosmetics § 73.2575 Titanium dioxide. (a) Identity and specifications. The color additive titanium dioxide shall conform in identity and...

2014-04-01

198

21 CFR 73.1575 - Titanium dioxide.  

... 2014-04-01 false Titanium dioxide. 73.1575 Section 73.1575...CERTIFICATION Drugs § 73.1575 Titanium dioxide. (a) Identity and specifications. (1) The color additive titanium dioxide shall conform in identity and...

2014-04-01

199

40 CFR 180.1195 - Titanium dioxide.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Titanium dioxide. 180.1195 Section 180.1195 Protection...Exemptions From Tolerances § 180.1195 Titanium dioxide. Titanium dioxide is exempted from the requirement of a...

2010-07-01

200

Carbon Dioxide Reduction Through Urban Forestry  

E-print Network

Carbon Dioxide Reduction Through Urban Forestry: Guidelines for Professional and Volunteer Tree; Simpson, James R. 1999. Carbon dioxide reduction through urban forestry of Agriculture; 237 p. Carbon dioxide reduction through urban forestry--Guidelines for professional and volunteer

Standiford, Richard B.

201

21 CFR 73.1575 - Titanium dioxide.  

Code of Federal Regulations, 2011 CFR

... 2011-04-01 false Titanium dioxide. 73.1575 Section 73.1575...CERTIFICATION Drugs § 73.1575 Titanium dioxide. (a) Identity and specifications. (1) The color additive titanium dioxide shall conform in identity and...

2011-04-01

202

21 CFR 73.2575 - Titanium dioxide.  

Code of Federal Regulations, 2013 CFR

... 2013-04-01 false Titanium dioxide. 73.2575 Section 73.2575... Cosmetics § 73.2575 Titanium dioxide. (a) Identity and specifications. The color additive titanium dioxide shall conform in identity and...

2013-04-01

203

21 CFR 172.480 - Silicon dioxide.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Silicon dioxide. 172.480 Section 172.480 Food and... Anticaking Agents § 172.480 Silicon dioxide. The food additive silicon dioxide may be safely used in food in accordance...

2012-04-01

204

40 CFR 180.1195 - Titanium dioxide.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Titanium dioxide. 180.1195 Section 180.1195 Protection...Exemptions From Tolerances § 180.1195 Titanium dioxide. Titanium dioxide is exempted from the requirement of a...

2011-07-01

205

21 CFR 73.2575 - Titanium dioxide.  

Code of Federal Regulations, 2011 CFR

... 2011-04-01 false Titanium dioxide. 73.2575 Section 73.2575... Cosmetics § 73.2575 Titanium dioxide. (a) Identity and specifications. The color additive titanium dioxide shall conform in identity and...

2011-04-01

206

21 CFR 73.2575 - Titanium dioxide.  

Code of Federal Regulations, 2012 CFR

... 2012-04-01 false Titanium dioxide. 73.2575 Section 73.2575... Cosmetics § 73.2575 Titanium dioxide. (a) Identity and specifications. The color additive titanium dioxide shall conform in identity and...

2012-04-01

207

21 CFR 73.1575 - Titanium dioxide.  

Code of Federal Regulations, 2013 CFR

... 2013-04-01 false Titanium dioxide. 73.1575 Section 73.1575...CERTIFICATION Drugs § 73.1575 Titanium dioxide. (a) Identity and specifications. (1) The color additive titanium dioxide shall conform in identity and...

2013-04-01

208

10 CFR 71.23 - General license: Plutonium-beryllium special form material.  

...false General license: Plutonium-beryllium special form material. 71.23 Section...23 General license: Plutonium-beryllium special form material. (a) A...fissile material in the form of plutonium-beryllium (Pu-Be) special form...

2014-01-01

209

10 CFR 71.23 - General license: Plutonium-beryllium special form material.  

Code of Federal Regulations, 2011 CFR

...false General license: Plutonium-beryllium special form material. 71.23 Section...23 General license: Plutonium-beryllium special form material. (a) A...fissile material in the form of plutonium-beryllium (Pu-Be) special form...

2011-01-01

210

10 CFR 71.23 - General license: Plutonium-beryllium special form material.  

Code of Federal Regulations, 2012 CFR

...false General license: Plutonium-beryllium special form material. 71.23 Section...23 General license: Plutonium-beryllium special form material. (a) A...fissile material in the form of plutonium-beryllium (Pu-Be) special form...

2012-01-01

211

10 CFR 71.23 - General license: Plutonium-beryllium special form material.  

Code of Federal Regulations, 2013 CFR

...false General license: Plutonium-beryllium special form material. 71.23 Section...23 General license: Plutonium-beryllium special form material. (a) A...fissile material in the form of plutonium-beryllium (Pu-Be) special form...

2013-01-01

212

Plutonium Uranium Extraction Facility Documented Safety Analysis  

SciTech Connect

This document provides the documented safety analysis (DSA) and Central Plateau Remediation Project (CP) requirements that apply to surveillance and maintenance (S&M) activities at the Plutonium-Uranium Extraction (PUREX) facility. This DSA was developed in accordance with DOE-STD-1120-98, ''Integration of Environment, Safety, and Health into Facility Disposition Activities''. Upon approval and implementation of this document, the current safety basis documents will be retired.

DODD, E.N.

2003-10-08

213

FIRE AND EXPLOSION TESTS OF PLUTONIUM GLOVEBOXES  

Microsoft Academic Search

To test the fire and explosion resistance of new plutonium metallurgy ;\\u000a gloveboxes and to obtain information pertinent to fire control, fire and ;\\u000a explosion tests were conducted in one of the gloveboxes. It was found that over ;\\u000a l0% oxygen is required for non-metal, and that over 5% oxygen is required for ;\\u000a freely burning metal fires. However, metal

Rhude

1962-01-01

214

NAS outlines best options for plutonium disposal  

Microsoft Academic Search

The best options for disposition of excess weapons-grade plutonium are fabrication into mixed-oxide fuel for use in existing reactors or vitrification with high-level radioactive waste, a National Academy of Sciences panel has concluded. The academy's Committee on International Security and Arms Control said a third option was burial in deep boreholes, although it said more research was needed to determine

Lobsenz

1994-01-01

215

Nuclear weapons and power-reactor plutonium  

Microsoft Academic Search

1-10 that for making nuclear bombs, 'reactor-grade' plutonium produced by the normal operation of uranium-fuelled power reactors is necessarily much inferior to specially made 'weapons-grade' Pu: so infe- rior in explosive power or predictability that its potential use by amateurs is not a serious problem and that governments would instead make the higher-performance weapons-grade Pu in special production reactors. Although

Amory B. Lovins

1980-01-01

216

Carbon dioxide and climate  

NASA Astrophysics Data System (ADS)

The earth's climate is getting warmer because of a buildup of carbon dioxide in the atmosphere that will continue well into the next century, according to a report released October 20 by the National Research Council (NRC), the research arm of the National Academy of Sciences. As the result of a 2-year study commissioned by Congress, the NRC's Carbon Dioxide Assessment Committee predicts a global temperature rise of as much as 4.5°C by the year 2100, enough to shift weather patterns, raise sea levels, and eliminate agriculture in some parts of the world. What's more, the trend seems inevitable— even drastic changes in our energy use would not prevent the warmup, according to the committee's findings.CO2, the major contributor to a thermal “greenhouse effect” that traps re-radiated heat in the atmosphere, has risen from a concentration of 315 parts per million (ppm) to 340 ppm in one generation, largely as a result of the use of fossil fuels. Sometime in the third quarter of the next century, the report predicts, the concentration will probably be double the current level. The result will be a global warming of surface air of between 1.5° and 4.5°C, with temperature rises relatively greater at the poles.

217

The carbonate complexation of plutonium(IV)  

SciTech Connect

Plutonium(IV) carbonate complexes are expected to be of particular importance in typical groundwaters at the Yucca Mountain site of the candidate nuclear waste repository being studied by the Nevada Nuclear Waste Storage Investigations Project. The chemistry of these complexes is also important in the areas of nuclear fuel reprocessing and purification, actinide separations, and environmental studies. This report describes initial experiments performed to determine the identity and equilibrium quotients of plutonium(IV) carbonate complexes. These experiments were performed at pH values between 7.2 and 9.6 using a spectrophotometric method. In addition, a brief review of the published literature on Pu(IV) carbonate complexes is presented. Since Pu(IV) exhibits low solubility in the near-neutral pH range, a complex-competition reaction where citrate ligands compete with carbonate ions for the plutonium will be employed. This will permit us to study the pure carbonate system; study the mixed carbonate/citrate system, and confirm and extend the literature work on the pure citrate system. The current experiments have demonstrated the existence of at least three distinct species in the pH region studied. This work will continue in the extended study of the pure citrate system, followed by the investigation of the citrate/carbonate complex/competition reaction. 9 refs., 4 figs., 2 tabs.

Hobart, D E; Palmer, P D; Newton, T W

1985-01-01

218

TRACKING SURPLUS PLUTONIUM FROM WEAPONS TO DISPOSITION  

SciTech Connect

Supporting nuclear nonproliferation and global security principles, beginning in 1994 the United States has withdrawn more than 50 metric tons (MT) of government-controlled plutonium from potential use in nuclear weapons. The Department of Energy (DOE), including the National Nuclear Security Administration, established protocols for the tracking of this "excess" and "surplus" plutonium, and for reconciling the current storage and utilization of the plutonium to show that its management is consistent with the withdrawal policies. Programs are underway to ensure the safe and secure disposition of the materials that formed a major part of the weapons stockpile during the Cold War, and growing quantities have been disposed as waste, after which they are not included in traditional nuclear material control and accountability (NMC&A) data systems. A combination of resources is used to perform the reconciliations that form the basis for annual reporting to DOE, to U.S. Department of State, and to international partners including the International Atomic Energy Agency.

Allender, J.; Beams, J.; Sanders, K.; Myers, L.

2013-07-16

219

Characterizing Surplus US Plutonium for Disposition - 13199  

SciTech Connect

The United States (US) has identified 61.5 metric tons (MT) of plutonium that is permanently excess to use in nuclear weapons programs, including 47.2 MT of weapons-grade plutonium. Surplus inventories will be stored safely by the Department of Energy (DOE) and then transferred to facilities that will prepare the plutonium for permanent disposition. The Savannah River National Laboratory (SRNL) operates a Feed Characterization program for the Office of Fissile Materials Disposition (OFMD) of the National Nuclear Security Administration (NNSA) and the DOE Office of Environmental Management (DOE-EM). SRNL manages a broad program of item tracking through process history, laboratory analysis, and non-destructive assay. A combination of analytical techniques allows SRNL to predict the isotopic and chemical properties that qualify materials for disposition through the Mixed Oxide (MOX) Fuel Fabrication Facility (MFFF). The research also defines properties that are important for other disposition paths, including disposal to the Waste Isolation Pilot Plant (WIPP) as transuranic waste (TRUW) or to high-level waste (HLW) systems. (authors)

Allender, Jeffrey S. [Savannah River National Laboratory, Aiken SC 29808 (United States)] [Savannah River National Laboratory, Aiken SC 29808 (United States); Moore, Edwin N. [Moore Nuclear Energy, LLC, Savannah River Site, Aiken SC 29808 (United States)] [Moore Nuclear Energy, LLC, Savannah River Site, Aiken SC 29808 (United States)

2013-07-01

220

Zirconia ceramics for excess weapons plutonium waste  

NASA Astrophysics Data System (ADS)

We synthesized a zirconia (ZrO 2)-based single-phase ceramic containing simulated excess weapons plutonium waste. ZrO 2 has large solubility for other metallic oxides. More than 20 binary systems A xO y-ZrO 2 have been reported in the literature, including PuO 2, rare-earth oxides, and oxides of metals contained in weapons plutonium wastes. We show that significant amounts of gadolinium (neutron absorber) and yttrium (additional stabilizer of the cubic modification) can be dissolved in ZrO 2, together with plutonium (simulated by Ce 4+, U 4+ or Th 4+) and impurities (e.g., Ca, Mg, Fe, Si). Sol-gel and powder methods were applied to make homogeneous, single-phase zirconia solid solutions. Pu waste impurities were completely dissolved in the solid solutions. In contrast to other phases, e.g., zirconolite and pyrochlore, zirconia is extremely radiation resistant and does not undergo amorphization. Baddeleyite (ZrO 2) is suggested as the natural analogue to study long-term radiation resistance and chemical durability of zirconia-based waste forms.

Gong, W. L.; Lutze, W.; Ewing, R. C.

2000-01-01

221

A Plutonium-Contaminated Wound, 1985, USA  

SciTech Connect

A hand injury occurred at a U.S. facility in 1985 involving a pointed shaft (similar to a meat thermometer) that a worker was using to remove scrap solid plutonium from a plastic bottle. The worker punctured his right index finger on the palm side at the metacarpal-phalangeal joint. The wound was not through-and- through, although it was deep. The puncture wound resulted in deposition of ~48 kBq of alpha activity from the weapons-grade plutonium mixture with a nominal 12 to 1 Pu-alpha to {sup 241}Am-alpha ratio. This case clearly showed that DTPA was very effective for decorporation of plutonium and americium. The case is a model for management of wounds contaminated with transuranics: (1) a team approach for dealing with all of the issues surrounding the incident, including the psychological, (2) early surgical intervention for foreign-body removal, (3) wound irrigation with DTPA solution, and (4) early and prolonged DTPA administration based upon bioassay and in vivo dosimetry.

Doran M. Christensen, DO, REAC /TS Associate Director and Staff Physician Eugene H. Carbaugh, CHP, Staff Scientist, Internal Dosimetry Manager, Pacific Northwest National Laboratory, Richland, Washington

2012-02-02

222

High temperature oxidation of plutonium-1 wt % gallium in 94. 5% nitrogen/5. 5% oxygen atmospheres  

SciTech Connect

The oxidation of plutonium-1 wt % gallium in 500 torr of a mixture of 94.5% nitrogen/5.5% oxygen has been investigated over the temperature range of 150 to 500/sup 0/C. This atmosphere typifies the atmospheres in the Rocky Flats inert glovebox lines. Rates of oxidation were nearly identical to the rates measured in an air atmosphere. The mechanism for the oxidation were nearly identical to the rates measured in an air atmosphere. The mechanism for the oxidation process involved three stages. Stage 1 was the buildup of a dense oxide film with a rate of growth determined by the diffusion of oxygen through the plutonium dioxide layer. Stage 2 involved a linear rate process equivalent to the rate of diffusion through an oxide film with a constant thickness and also equivalent to the rate of crack and pore formation in the oxide. Stage 3 was a linear interface controlled reaction resulting from the cracking and spalling of the oxide layer.

Stakebake, J L; Lewis, L A

1986-11-03

223

Carbon Dioxide Capture and Disposal  

Microsoft Academic Search

Unless carbon dioxide from fossil fuel combustion is captured and disposed of safely and permanently, the concerns over climate change will eventually lead to the demise of fossil fuels. Because of their importance in today's energy market the phasing out of fossil fuels would likely precipitate a major energy crisis. Mineral sequestration and extraction of carbon dioxide from the air

K. S. Lackner

2002-01-01

224

Reaction products of chlorine dioxide.  

PubMed Central

Inspection of the available literature reveals that a detailed investigation of the aqueous organic chemistry of chlorine dioxide and systematic identification of products formed during water disinfection has not been considered. This must be done before an informed assessment can be made of the relative safety of using chlorine dioxide as a disinfectant alternative to chlorine. Although trihalomethanes are generally not formed by the action of chlorine dioxide, the products of chlorine dioxide treatment of organic materials are oxidized species, some of which also contain chlorine. The relative amounts of species types may depend on the amount of chlorine dioxide residual maintained and the concentration and nature of the organic material present in the source water. The trend toward lower concentrations of chlorinated by-products with increasing ClO2 concentration, which was observed with phenols, has not been observed with natural humic materials as measured by the organic halogen parameter. Organic halogen concentrations have been shown to increase with increasing chlorine dioxide dose, but are much lower than those observed when chlorine is applied. Aldehydes have been detected as apparent by-products of chlorine dioxide oxidation reactions in a surface water that is a drinking water source. Some other nonchlorinated products of chlorine dioxide treatment may be quinones and epoxides. The extent of formation of these moieties within the macromolecular humic structure is also still unknown. PMID:7151750

Stevens, A A

1982-01-01

225

Coral reefs and carbon dioxide  

SciTech Connect

This commentary argues the conclusion from a previous article, which investigates diurnal changes in carbon dioxide partial pressure and community metabolism on coral reefs, that coral `reefs might serve as a sink, not a source, for atmospheric carbon dioxide.` Commentaries from two groups are given along with the response by the original authors, Kayanne et al. 27 refs.

Buddemeier, R.W. [Kansas Geological Survey, Lawrence, KS (United States)

1996-03-01

226

Geomorphology of plutonium in the Northern Rio Grande  

SciTech Connect

Nearly all of the plutonium in the natural environment of the Northern Rio Grande is associated with soils and sediment, and river processes account for most of the mobility of these materials. A composite regional budget for plutonium based on multi-decadal averages for sediment and plutonium movement shows that 90 percent of the plutonium moving into the system is from atmospheric fallout. The remaining 10 percent is from releases at Los Alamos. Annual variation in plutonium flux and storage exceeds 100 percent. The contribution to the plutonium budget from Los Alamos is associated with relatively coarse sediment which often behaves as bedload in the Rio Grande. Infusion of these materials into the main stream were largest in 1951, 1952, 1957, and 1968. Because of the schedule of delivery of plutonium to Los Alamos for experimentation and weapons manufacturing, the latter two years are probably the most important. Although the Los Alamos contribution to the entire plutonium budget was relatively small, in these four critical years it constituted 71--86 percent of the plutonium in bedload immediately downstream from Otowi.

Graf, W.L. [Arizona Univ., Tempe, AZ (United States). Dept., of Geography

1993-03-01

227

Real-time measurement of plutonium in air by direct-inlet surface ionization mass spectrometry. Status report  

SciTech Connect

A new technique is being developed for monitoring low-level airborne plutonium on a real-time basis. The technique is based on surface ionization mass spectrometry of airborne particles. It will be capable of measuring plutonium concentrations below the maximum permissible concentration (MPC) level. A complete mass spectrometer was designed and constructed for this purpose. Major components which were developed and made operational for the instrument include an efficient inlet for directly sampling particles in air, a wide dynamic range ion detector and a minicomputer-based ion-burst measurement system. Calibration of the direct-inlet mass spectrometer (DIMS) was initiated to establish the instrument's response to plutonium dioxide as a function of concentration and particle size. This work revealed an important problem - bouncing of particles upon impact with the ionizing filament. Particle bounce results in a significant loss of measurement sensitivity. The feasibility of using an oven ionizer to overcome the particle bounce problem has been demonstrated. A rhenium oven ionizer was designed and constructed for the purpose of trapping particles which enter via the direct inlet. High-speed particles were trapped in the oven yielding a measurement sensitivity comparable to that for particles which are preloaded. Development of the Pu DIMS can now be completed by optimizing the oven design and calibrating the instrument's performance with UO/sub 2/ and CeO/sub 2/ particles as analogs to PuO/sub 2/ particles.

Stoffels, J.J.

1980-04-01

228

Plutonium and Cesium Colloid Mediated Transport  

NASA Astrophysics Data System (ADS)

Plutonium and cesium have been released to the environment at many different locations worldwide and are present in spent fuel at significant levels. Accurate understanding of the mechanisms that control their fate and transport in the environment is important for the management of contaminated sites, for forensic applications, and for the development of robust repositories for the disposal of spent nuclear fuel and nuclear waste. Plutonium, which can be present in the environment in multiple oxidations states and various chemical forms including amorphous oxy(hydr)oxide phases, adsorbs/adheres very strongly to geological materials and is usually immobile in all its chemical forms. However, when associated with natural colloids, it has the potential to migrate significant distances from its point of release. Like plutonium, cesium is not very mobile and tends to remain adhered to geological materials near its release point, although its transport can be enhanced by natural colloids. However, the reactivity of plutonium and cesium are very different, so their colloid-mediated transport might be significantly different in subsurface environments. In this study, we performed controlled experiments in two identically-prepared columns; one dedicated to Pu and natural colloid transport experiments, and the other to Cs and colloid experiments. Multiple flow-through experiments were conducted in each column, with the effluent solutions being collected and re-injected into the same column two times to examine the persistence and scaling behavior of the natural colloids, Pu and Cs. The data show that that a significant fraction of colloids were retained in the first elution through each column, but the eluted colloids collected from the first run transported almost conservatively in subsequent runs. Plutonium transport tracked natural colloids in the first run but deviated from the transport of natural colloids in the second and third runs. Cesium transport tracked natural colloid transport in all re-injections. The data will be discussed in terms of natural colloid properties, including size distribution and electrokinetic properties, as well as the reactive transport behavior of Pu and Cs. We will also discuss the implications of the results for colloid-mediated contaminant transport, management of contaminated sites and forensic data interpretation.

Boukhalfa, H.; Dittrich, T.; Reimus, P. W.; Ware, D.; Erdmann, B.; Wasserman, N. L.; Abdel-Fattah, A. I.

2013-12-01

229

Carbon Dioxide Capture and Disposal  

NASA Astrophysics Data System (ADS)

Unless carbon dioxide from fossil fuel combustion is captured and disposed of safely and permanently, the concerns over climate change will eventually lead to the demise of fossil fuels. Because of their importance in today's energy market the phasing out of fossil fuels would likely precipitate a major energy crisis. Mineral sequestration and extraction of carbon dioxide from the air are two advanced technologies for carbon sequestration that aim at maintaining access to the vast fossil energy resources for centuries to come. While it is straightforward to dispose of carbon dioxide in limited amounts and for a limited time, permanent disposal of trillions of tons of carbon poses serious challenges. The formation of solid mineral carbonates from readily available minerals would provide safe and permanent storage. Capture of carbon dioxide from air makes it possible to sequester carbon dioxide emissions from sources other than power plants. This is important considering that even the relatively minor reductions suggested by the Kyoto Accord would have required the US to eliminate carbon dioxide emissions comparable to those of the entire 1990 coal fired power plant fleet. Capture of carbon dioxide from the air, would make it possible to close the carbon cycle in the transportation sector without phasing out liquid hydrocarbon fuels. It eliminates the need for long distance transport of carbon dioxide and allows the continued use of the existing energy infrastructure. Mineral sequestration at remote sites combined with on site carbon dioxide capture from air, would allow for long term stabilization of atmospheric carbon dioxide levels. I will outline the current state of the technology and point to advances required before these approaches are ready for large-scale implementation.

Lackner, K. S.

2002-05-01

230

Determination of plutonium dioxide surface areas from x-ray crystallite sizes  

Microsoft Academic Search

An empirical relationship between PuOâ surface areas and the x-ray crystallite sizes is described. This relationship permits the oxide surface area to be determined from the easily measured x-ray crystallite size. Fourteen samples of ground and calcined oxide were used for the analyses. It is shown that as crystallite size decreases the surface area increases and that this change is

J STAKEBAKE

1982-01-01

231

Determination of plutonium dioxide surface areas from x-ray crystallite sizes  

SciTech Connect

An empirical relationship between PuO/sub 2/ surface areas and the x-ray crystallite sizes is described. This relationship permits the oxide surface area to be determined from the easily measured x-ray crystallite size. Fourteen samples of ground and calcined oxide were used for the analyses. It is shown that as crystallite size decreases the surface area increases and that this change is systematic and predictable.

Stakebake, J.L.

1982-12-01

232

A STUDY OF THE DEPOSITION AND RETENTION OF PLUTONIUM DIOXIDE IN RATS (thesis)  

Microsoft Academic Search

Four groups of six l50 to 175 g female rats were exposed for 45 minutes ; to a PuOâ aerosol generated by aspiration of an aqueous PuOâ ; suspension. Particle size measurements made with a point-to-plane electrostatic ; precipitator and an electron microscope indicated the aerosol had a count median ; diameter of 0.19 mu with sigma g = 2.08.

Boecker

1959-01-01

233

Uranium dioxide electrolysis  

DOEpatents

This is a single stage process for treating spent nuclear fuel from light water reactors. The spent nuclear fuel, uranium oxide, UO.sub.2, is added to a solution of UCl.sub.4 dissolved in molten LiCl. A carbon anode and a metallic cathode is positioned in the molten salt bath. A power source is connected to the electrodes and a voltage greater than or equal to 1.3 volts is applied to the bath. At the anode, the carbon is oxidized to form carbon dioxide and uranium chloride. At the cathode, uranium is electroplated. The uranium chloride at the cathode reacts with more uranium oxide to continue the reaction. The process may also be used with other transuranic oxides and rare earth metal oxides.

Willit, James L. (Batavia, IL); Ackerman, John P. (Prescott, AZ); Williamson, Mark A. (Naperville, IL)

2009-12-29

234

Carbon Dioxide Landscape  

NASA Technical Reports Server (NTRS)

7 July 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a mid-summer view of the south polar residual cap at full MOC resolution, 1.5 m (5 ft) per pixel. During each of the three summers since the start of the MGS mapping mission in March 1999, the scarps that form mesas and pits in the 'Swiss cheese'-like south polar terrain have retreated an average of about 3 meters (1 yard). The material is frozen carbon dioxide; another 3 meters or so of each scarp is expected to be removed during the next summer, in late 2005. This image is located near 86.0oS, 350.8oW, and covers an area about 1.5 km (0.9 mi) wide. Sunlight illuminates the scene from the top/upper left.

2004-01-01

235

Update on the Department of Energy's 1994 plutonium vulnerability assessment for the plutonium finishing plant  

SciTech Connect

A review of the environmental, safety, and health vulnerabilities associated with the continued storage of PFP's inventory of plutonium bearing materials and other SNM. This report re-evaluates the five vulnerabilities identified in 1994 at the PFP that are associated with SNM storage. This new evaluation took a more detailed look and applied a risk ranking process to help focus remediation efforts.

HERZOG, K.R.

1999-09-01

236

Handling, Storage, and Disposition of Plutonium and Uranium  

Microsoft Academic Search

The need to address topics of handling, storage, and disposal of plutonium and uranium is driven by concern about hazards posed by the element and by the worldwide quantity of civilian and military materials. The projected inventory of separated civilian plutonium for use in fabricating mixed-oxide (MOX) reactor fuel during initial decades of this century is constant at about 120

John M. Haschke; Jerry L. Stakebake

2011-01-01

237

THE DETERMINATION OF SMALL AMOUNTS OF NEPTUNIUM IN PLUTONIUM METAL  

Microsoft Academic Search

A method is described for determining the neptunium content (10 to 2000 ; ppm) of plutonium metal. The neptunium is separated from plutonium by solvent ; extraction with 2-thenoyltrifluoroacetone and then determined with a square-wave ; polarograph. Results show neptunium contents ranging from 25 to 500 ppm. The ; precision at these two levels is about plus or minus 10

L. J. Slee; G. Phillips; E. N. Jenkins

1959-01-01

238

Using the IFR to dispose of excess weapons plutonium  

Microsoft Academic Search

Plutonium is a man-made radioactive element with a long half-life. The only way to dispose of plutonium permanently is by causing it to fission. The fission process is efficient only in a fast neutron spectrum, and multiple recycle with a minimal loss is required to approach complete destruction. To be consistent with nonproliferation objectives, the process should be compatible with

W. H. Hannum; D. C. Wade

1997-01-01

239

10 CFR 71.88 - Air transport of plutonium.  

Code of Federal Regulations, 2012 CFR

...2012-01-01 2012-01-01 false Air transport of plutonium. 71.88 Section...Controls and Procedures § 71.88 Air transport of plutonium. (a...or delivered to a carrier for air transport unless: (1) The...

2012-01-01

240

10 CFR 71.88 - Air transport of plutonium.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2010-01-01 false Air transport of plutonium. 71.88 Section...Controls and Procedures § 71.88 Air transport of plutonium. (a...or delivered to a carrier for air transport unless: (1) The...

2010-01-01

241

10 CFR 71.88 - Air transport of plutonium.  

Code of Federal Regulations, 2013 CFR

...2013-01-01 2013-01-01 false Air transport of plutonium. 71.88 Section...Controls and Procedures § 71.88 Air transport of plutonium. (a...or delivered to a carrier for air transport unless: (1) The...

2013-01-01

242

10 CFR 71.88 - Air transport of plutonium.  

...2014-01-01 2014-01-01 false Air transport of plutonium. 71.88 Section...Controls and Procedures § 71.88 Air transport of plutonium. (a...or delivered to a carrier for air transport unless: (1) The...

2014-01-01

243

10 CFR 71.88 - Air transport of plutonium.  

Code of Federal Regulations, 2011 CFR

...2011-01-01 2011-01-01 false Air transport of plutonium. 71.88 Section...Controls and Procedures § 71.88 Air transport of plutonium. (a...or delivered to a carrier for air transport unless: (1) The...

2011-01-01

244

Plutonium in the arctic marine environment--a short review.  

PubMed

Anthropogenic plutonium has been introduced into the environment over the past 50 years as the result of the detonation of nuclear weapons and operational releases from the nuclear industry. In the Arctic environment, the main source of plutonium is from atmospheric weapons testing, which has resulted in a relatively uniform, underlying global distribution of plutonium. Previous studies of plutonium in the Kara Sea have shown that, at certain sites, other releases have given rise to enhanced local concentrations. Since different plutonium sources are characterised by distinctive plutonium-isotope ratios, evidence of a localised influence can be supported by clear perturbations in the plutonium-isotope ratio fingerprints as compared to the known ratio in global fallout. In Kara Sea sites, such perturbations have been observed as a result of underwater weapons tests at Chernaya Bay, dumped radioactive waste in Novaya Zemlya, and terrestrial runoff from the Ob and Yenisey Rivers. Measurement of the plutonium-isotope ratios offers both a means of identifying the origin of radionuclide contamination and the influence of the various nuclear installations on inputs to the Arctic, as well as a potential method for following the movement of water and sediment loads in the rivers. PMID:15258672

Skipperud, Lindis

2004-06-18

245

Mound Laboratory plutonium study: Presentation to the scientific review panel  

Microsoft Academic Search

This paper describes the Mound plutonium study. The objectives of the project were to evaluate the inventory of plutonium 238 in the environment at Mound, determine the source, and alleviate potential health hazards. Analysis of soils, water, vegetation, fishes, and runoff were performed.

D. R. Rogers; W. H. Westendorf; J. R. McClain

1975-01-01

246

Recommended plutonium release fractions from postulated fires. Final report  

SciTech Connect

This report was written at the request of EG&G Rocky Flats, Inc. in support of joint emergency planning for the Rocky Flats Plant (RFP) by EG&G and the State of Colorado. The intent of the report is to provide the State of Colorado with an independent assessment of any respirable plutonium releases that might occur in the event of a severe fire at the plant. Fire releases of plutonium are of interest because they have been used by EG&G to determine the RFP emergency planning zones. These zones are based on the maximum credible accident (MCA) described in the RFP Final Environmental Impact Statement (FEIS) of 1980, that MCA is assumed to be a large airplane crashing into a RFP plutonium building.The objective of this report was first, to perform a worldwide literature review of relevant release experiments from 1960 to the present and to summarize those findings, and second, to provide recommendations for application of the experimental data to fire release analyses at Rocky Flats. The latter step requires translation between experimental and expected RFP accident parameters, or ``scaling.`` The parameters of particular concern are: quantities of material, environmental parameters such as the intensity of a fire, and the physico-chemical forms of the plutonium. The latter include plutonium metal, bulk plutonium oxide powder, combustible and noncombustible wastes contaminated with plutonium oxide powder, and residues from plutonium extraction processes.

Kogan, V.; Schumacher, P.M.

1993-12-01

247

Processing of Non-PFP Plutonium Oxide in Hanford Plants  

SciTech Connect

Processing of non-irradiated plutonium oxide, PuO2, scrap for recovery of plutonium values occurred routinely at Hanford’s Plutonium Finishing Plant (PFP) in glovebox line operations. Plutonium oxide is difficult to dissolve, particularly if it has been high-fired; i.e., calcined to temperatures above about 400°C and much of it was. Dissolution of the PuO2 in the scrap typically was performed in PFP’s Miscellaneous Treatment line using nitric acid (HNO3) containing some source of fluoride ion, F-, such as hydrofluoric acid (HF), sodium fluoride (NaF), or calcium fluoride (CaF2). The HNO3 concentration generally was 6 M or higher whereas the fluoride concentration was ~0.5 M or lower. At higher fluoride concentrations, plutonium fluoride (PuF4) would precipitate, thus limiting the plutonium dissolution. Some plutonium-bearing scrap also contained PuF4 and thus required no added fluoride. Once the plutonium scrap was dissolved, the excess fluoride was complexed with aluminum ion, Al3+, added as aluminum nitrate, Al(NO3)3•9H2O, to limit collateral damage to the process equipment by the corrosive fluoride. Aluminum nitrate also was added in low quantities in processing PuF4.

Jones, Susan A.; Delegard, Calvin H.

2011-03-10

248

Plutonium Finishing Plant operational readiness review. Revision 1  

Microsoft Academic Search

This plan describes the readiness review process to be used to meet the objectives to support the restart of the Plutonium Finishing Plant (PFP) to convert the chemically-acting plutonium-bearing materials to a form suitable for processing in the remote mechanical ``C`` (RMC) line. The scope of this plan will cover the restart readiness review needs of the PFP Material Stabilization

Eschenbaum

1992-01-01

249

Studies of a Liquid Anode for Plutonium Electrorefining  

Microsoft Academic Search

We are developing a solvent anode as an alternate method for producing plutonium metal of high purity by an electrorefining process. Our goals are to produce metal of 99.98% purity with an anode residue containing less than 2% of the plutonium in the feed material. If we are successful, we will design and demonstrate a system utilizing semi-continuous and remotely

David F. Bowersox; James A. Mcneese; Dana C. Christensen

1987-01-01

250

25. Plutonium Recovery From Contaminated Materials, Architectural Plans & Details, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

25. Plutonium Recovery From Contaminated Materials, Architectural Plans & Details, Building 232-Z, U.S. Atomic Energy Commission, Hanford Atomic Products Operation, General Electric Company, Dwg. No. H-2-23105, 1959. - Plutonium Finishing Plant, Waste Incinerator Facility, 200 West Area, Richland, Benton County, WA

251

26. Plutonium Recovery From Contaminated Materials, Architectural Elevations, Sections & ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

26. Plutonium Recovery From Contaminated Materials, Architectural Elevations, Sections & Dets., Building 232-Z, U.S. Atomic Energy Commission, Hanford Atomic Products Operation, General Electric Company, Dwg. No. H-2-23106, 1959. - Plutonium Finishing Plant, Waste Incinerator Facility, 200 West Area, Richland, Benton County, WA

252

CARBON DIOXIDE AND OUR OCEAN LEGACY  

E-print Network

of carbon dioxide from the atmosphere, or nearly half of the fossil fuel carbon emissions over this periodCARBON DIOXIDE AND OUR OCEAN LEGACY G Carbon Dioxide: Our Role The United States is the single. Every day the average American adds about 118 pounds of carbon dioxide to the atmos- phere, due largely

253

Uncertainties on lung doses from inhaled plutonium.  

PubMed

In a recent epidemiological study, Bayesian uncertainties on lung doses have been calculated to determine lung cancer risk from occupational exposures to plutonium. These calculations used a revised version of the Human Respiratory Tract Model (HRTM) published by the ICRP. In addition to the Bayesian analyses, which give probability distributions of doses, point estimates of doses (single estimates without uncertainty) were also provided for that study using the existing HRTM as it is described in ICRP Publication 66; these are to be used in a preliminary analysis of risk. To infer the differences between the point estimates and Bayesian uncertainty analyses, this paper applies the methodology to former workers of the United Kingdom Atomic Energy Authority (UKAEA), who constituted a subset of the study cohort. The resulting probability distributions of lung doses are compared with the point estimates obtained for each worker. It is shown that mean posterior lung doses are around two- to fourfold higher than point estimates and that uncertainties on doses vary over a wide range, greater than two orders of magnitude for some lung tissues. In addition, we demonstrate that uncertainties on the parameter values, rather than the model structure, are largely responsible for these effects. Of these it appears to be the parameters describing absorption from the lungs to blood that have the greatest impact on estimates of lung doses from urine bioassay. Therefore, accurate determination of the chemical form of inhaled plutonium and the absorption parameter values for these materials is important for obtaining reliable estimates of lung doses and hence risk from occupational exposures to plutonium. PMID:21692652

Puncher, Matthew; Birchall, Alan; Bull, Richard K

2011-10-01

254

Hydride-catalyzed corrosion of plutonium by air: Initiation by plutonium monoxide monohydride  

SciTech Connect

Chemistry and kinetics of air reactions with plutonium monoxide monohydride (PuOH) and with mixtures of the oxide hydride and plutonium metal are defined by results of pressure-volume-temperature (PVT) measurements. Test with specimens prepared by total and partial corrosion of plutonium in 0.05 M sodium chloride solution show that reaction of residual water continues to generate H{sub 2} after liquid water is removed by evacuation. Rapid exposure of PuOH to air at room temperature does not produce a detectable reaction, but similar exposure of a partially corroded metal sample containing Pu and PuOH results in hydride (PuH{sub x})-catalyzed corrosion of the residual Pu. Kinetics of he first-order reaction resulting in formation of the PuH{sub x} catalyst and of the indiscriminate reaction of N{sub 2} and O{sub 2} with plutonium metal are defined. The rate of the catalyzed Pu+air reaction is independent of temperature (E{sub a} = 0), varies as the square of air pressure, and equals 0.78 {+-} 0.03 g Pu/cm{sup 2} min in air at one atmosphere. The absence of pyrophoric behavior for PuOH and differences in the reactivities of PuOH and PuOH + Pu mixtures are attributed to kinetic control by gaseous reaction products. Thermodynamic properties of the oxide hydride are estimated, particle size distributions of corrosion products are presented, and potential hazards associated with products formed by aqueous corrosion of plutonium are discussed.

Allen, T.H.; Haschke, J.M.

1998-06-01

255

Carbon Dioxide Sequestration Industrial-scale processes are available for separating carbon dioxide from the post-  

E-print Network

Carbon Dioxide Sequestration Industrial-scale processes are available for separating carbon dioxide dioxide separation and sequestration because the lower cost of carbon dioxide separation from for injection of carbon dioxide into oil or gas-bearing formations. An advantage of sequestration involving

256

Prototype fast neutron counter for the assay of impure plutonium  

SciTech Connect

A fast coincident neutron counter using liquid scintillators and gamma-ray/neutron pulse-shape discrimination has been constructed for the analysis of plutonium samples with unknown self-multiplication and (..cap alpha..,n) production. The counter was used to measure plutonium-bearing materials that cover a range of masses and (..cap alpha..,n) reaction rates of importance to the safeguards community. Measured values of the /sup 240/Pu effective mass differed, on average, from their declared values by 0.4% for plutonium oxides and by -2.2% for metal and MgO-loaded samples. Poorer results were obtained for materials with large (..cap alpha..,n) reaction rates and low self-multiplication such as plutonium ash and plutonium fluoride.

Wachter, J.R.; Adams, E.L.; Ensslin, N.

1987-01-01

257

Preparation of Pure Plutonium Metal Standards for Nondestructive Assay  

SciTech Connect

To calibrate neutron coincidence and neutron multiplicity counters for passive assay of plutonium, certain detector parameters must be determined. When one is using small plutonium metal samples, biases can be introduced from non-zero multiplication and impurities. This paper describes preparing small, pure plutonium metal standards with well-known geometries to enable accurate multiplication corrections and with acceptably low levels of impurities. To minimize multiplication, these standards are designed as 2-cm-diameter foils with varying thicknesses and masses of 1.4, 3.6, and 7.2 g plutonium. These standards will significantly improve characterization and calibration of neutron coincidence and multiplicity counters. They can also be equally useful for gamma-ray spectrometry and calorimetry. Five sets will be made: four for other US Department of Energy plutonium facilities, and one set to remain at Los Alamos. We will also describe other nondestructive assay standards that are planned for the next few years.

S. -T. Hsue; J. E. Stewart; M. S. Krick

2000-11-01

258

Modelling the distribution of plutonium in the Pacific Ocean.  

PubMed

An Oceanic General Circulation Model (OGCM) including a plutonium scavenging model as well as an advection-diffusion model has been developed for modelling the distribution of plutonium in the Pacific Ocean. Calculated 239, 240Pu water profile concentrations and 239, 240Pu inventories in water and sediment of the Pacific Ocean have showed a reasonable agreement with the experimental results. The presence of local fallout plutonium in central North Pacific waters has been confirmed. The observed 240Pu/239Pu mass ratios confirm that plutonium originating from local fallout from nuclear weapons tests carried out at Bikini and Enewetak Atolls is more rapidly removed from surface waters to deeper waters than plutonium originating from global fallout. The developed OGCM can be used for modelling the dispersion of other non-conservative tracers in the ocean as well. PMID:12860091

Nakano, Masanao; Povinec, Pavel P

2003-01-01

259

Estimates of radiological risk from a terrorist attack using plutonium.  

PubMed

The possible use of radioactivity dispersal devices by terrorist groups has been recently reported in the news. In this paper, we discuss the threat of terrorist attacks by plutonium, with particular attention to the dispersal of plutonium by explosion or fire. Doses resulting from inhalation of radioactive aerosol induced by a plutonium explosion or fire are simulated using a Gaussian plume model (the HOTSPOT code) for different meteorological conditions. Ground contamination and resuspension of dust are also considered in the simulations. Our simulations suggest that acute effects from a plutonium dispersal attack are very unlikely. For late stochastic effects, the explosion poses a greater hazard than fire. However, even in the worst-case scenario, the dispersed plutonium would cause relatively few excess cancers (around 80 in a city of 2 million inhabitants) after many years from the explosion, and these excess cancers would remain undetected against the background of cancer fatalities. PMID:12201055

Durante, Marco; Manti, Lorenzo

2002-06-01

260

Americium characterization by X-ray fluorescence and absorption spectroscopy in plutonium uranium mixed oxide  

NASA Astrophysics Data System (ADS)

Plutonium uranium mixed oxide (MOX) fuels are currently used in nuclear reactors. The actinides in these fuels need to be analyzed after irradiation for assessing their behaviour with regard to their environment and the coolant. In this work the study of the atomic structure and next-neighbour environment of Am in the (Pu,U)O2 lattice in an irradiated (60 MW d kg-1) MOX sample was performed employing micro-X-ray fluorescence (µ-XRF) and micro-X-ray absorption fine structure (µ-XAFS) spectroscopy. The chemical bonds, valences and stoichiometry of Am (˜0.66 wt%) are determined from the experimental data gained for the irradiated fuel material examined in its peripheral zone (rim) of the fuel. In the irradiated sample Am builds up as Am3+ species within an [AmO8]13- coordination environment (e.g. >90%) and no (<10%) Am(IV) or (V) can be detected in the rim zone. The occurrence of americium dioxide is avoided by the redox buffering activity of the uranium dioxide matrix.

Degueldre, Claude; Cozzo, Cedric; Martin, Matthias; Grolimund, Daniel; Mieszczynski, Cyprian

2013-06-01

261

Carbon Dioxide and Ocean Acidification  

NSDL National Science Digital Library

Demonstrates the affect of increased dissolved carbon dioxide on water pH using a cheap, non-toxic acid/base indicator. Students bubble breath through a straw into red cabbage juice and note the color change.

Lewis, Chris

262

Extraction and Purification of Plutonium by a Tertiary Amine; EXTRACTION ET PURIFICATION DU PLUTONIUM PAR UNE AMINE TERTIAIRE  

Microsoft Academic Search

Trilaurylamins diluted with a paraffinic solvent (dodecane) was studied ; as part of the research dealing with the separation and purification of plutonium. ; The physical properties (solubility of nitrates in the amine as a function of ; temperature) and the resistance to radiation of this substance were examined. ; The extraction characteristics of nitric solutions of plutonium, uranium, and

M. de Trentinian; A. Chesne

1960-01-01

263

A titrimetric method for the sequential determination of thorium and plutonium  

Microsoft Academic Search

A method for the sequential determination of thorium and plutonium has been developed. In the sample solution containing thorium and plutonium, thorium is first determined by complexometric titration with EDTA and then in the same solution plutonium is determined by redox titration employing potentiometry. Prior to the determination of plutonium, EDTA is destroyed by fuming with concentrated HClO4. Thorium is

Keshav Chander; S. P. Hasilkar; S. G. Marathe

1991-01-01

264

Behavior of plutonium and americium at liquid cadmium cathode in molten LiCl–KCl electrolyte  

Microsoft Academic Search

The effects of the electrochemical conditions on the behavior of plutonium and proper conditions for plutonium recovery at the liquid cadmium cathode (LCC) used in the pyrometallurgical reprocessing were studied by the electrotransport experiments with small, not stirred electrodes. Plutonium was successfully collected up to 7.75 wt% without disturbance by solid phase formation at the surface. Plutonium collected beyond saturation

Masatoshi Iizuka; Koich Uozumi; Tadashi Inoue; Takashi Iwai; Osamu Shirai; Yasuo Arai

2001-01-01

265

Tags to Track Illicit Uranium and Plutonium  

SciTech Connect

With the expansion of nuclear power, it is essential to avoid nuclear materials from falling into the hands of rogue nations, terrorists, and other opportunists. This paper examines the idea of detection and attribution tags for nuclear materials. For a detection tag, it is proposed to add small amounts [about one part per billion (ppb)] of {sup 232}U to enriched uranium to brighten its radioactive signature. Enriched uranium would then be as detectable as plutonium and thus increase the likelihood of intercepting illicit enriched uranium. The use of rare earth oxide elements is proposed as a new type of 'attribution' tag for uranium and thorium from mills, uranium and plutonium fuels, and other nuclear materials. Rare earth oxides are chosen because they are chemically compatible with the fuel cycle, can survive high-temperature processing operations in fuel fabrication, and can be chosen to have minimal neutronic impact within the nuclear reactor core. The mixture of rare earths and/or rare earth isotopes provides a unique 'bar code' for each tag. If illicit nuclear materials are recovered, the attribution tag can identify the source and lot of nuclear material, and thus help police reduce the possible number of suspects in the diversion of nuclear materials based on who had access. (authors)

Haire, M. Jonathan; Forsberg, Charles W. [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN, 37831-6166 (United States)

2007-07-01

266

Co-Design: Fabrication of Unalloyed Plutonium  

SciTech Connect

The successful induction casting of plutonium is a challenge which requires technical expertise in areas including physical metallurgy, surface and corrosion chemistry, materials science, electromagnetic engineering and a host of other technologies all which must be applied in concert. Here at LANL, we are employing a combined experimental and computational approach to design molds and develop process parameters needed to produce desired temperature profiles and improved castings. Computer simulations are performed using the commercial code FLOW-3D and the LANL ASC computer code TRUCHAS to reproduce the entire casting process starting with electromagnetic or radiative heating of the mold and metal and continuing through pouring with coupled fluid flow, heat transfer and non-isothermal solidification. This approach greatly reduces the time required to develop a new casting designs and also increases our understanding of the casting process, leading to a more homogeneous, consistent product and better process control. We will discuss recent casting development results in support of unalloyed plutonium rods for mechanical testing.

Korzekwa, Deniece R. [Los Alamos National Laboratory; Knapp, Cameron M. [Los Alamos National Laboratory; Korzekwa, David A. [Los Alamos National Laboratory; Gibbs, John W [Northwestern University

2012-07-25

267

Management of disused plutonium sealed sources  

SciTech Connect

The Global Threat Reduction Initiative's (GTRI) Offsite Source Recovery Project (OSRP) has been recovering excess and unwanted radioactive sealed sources since 1999, including more than 2,400 Plutonium (Pu)-238 sealed sources and 653 Pu-239-bearing sources that represent more than 10% of the total sources recovered by GTRI/OSRP to date. These sources have been recovered from hundreds of sites within the United States (US) and around the world. OSRP grew out of early efforts at the Los Alamos National Laboratory (LANL) to recover and disposition excess Plutonium-239 (Pu-239) sealed sources that were distributed in the 1960s and 1970s under the Atoms for Peace Program, a loan-lease program that serviced 31 countries, as well as domestic users. In the conduct of these recovery operations, GTRI/OSRP has been required to solve problems related to knowledge-of-inventory, packaging and transportation of fissile and heat-source materials, transfer of ownership, storage of special nuclear material (SNM) both at US Department of Energy (DOE) facilities and commercially, and disposal. Unique issues associated with repatriation from foreign countries, including end user agreements required by some European countries and denials of shipment, will also be discussed.

Whitworth, Julia Rose [Los Alamos National Laboratory; Pearson, Michael W [Los Alamos National Laboratory; Abeyta, Cristy [Los Alamos National Laboratory

2010-01-01

268

AMS of the Minor Plutonium Isotopes  

NASA Astrophysics Data System (ADS)

VERA, the Vienna Environmental Research Accelerator, is especially equipped for the measurement of actinides, and performs a growing number of measurements on environmental samples. While AMS is not the optimum method for each particular plutonium isotope, the possibility to measure 239Pu, 240Pu, 241Pu, 242Pu and 244Pu on the same AMS sputter target is a great simplification. We have obtained a first result on the global fallout value of 244Pu/239Pu = (5.7 ± 1.0) × 10-5 based on soil samples from Salzburg prefecture, Austria. Furthermore, we suggest using the 242Pu/240Pu ratio as an estimate of the initial 241Pu/239Pu ratio, which allows dating of the time of irradiation based solely on Pu isotopes. We have checked the validity of this estimate using literature data, simulations, and environmental samples from soil from the Salzburg prefecture (Austria), from the shut down Garigliano Nuclear Power Plant (Sessa Aurunca, Italy) and from the Irish Sea near the Sellafield nuclear facility. The maximum deviation of the estimated dates from the expected ages is 6 years, while relative dating of material from the same source seems to be possible with a precision of less than 2 years. Additional information carried by the minor plutonium isotopes may allow further improvements of the precision of the method.

Steier, P.; Hrnecek, E.; Priller, A.; Quinto, F.; Srncik, M.; Wallner, A.; Wallner, G.; Winkler, S.

2013-01-01

269

AMS of the Minor Plutonium Isotopes.  

PubMed

VERA, the Vienna Environmental Research Accelerator, is especially equipped for the measurement of actinides, and performs a growing number of measurements on environmental samples. While AMS is not the optimum method for each particular plutonium isotope, the possibility to measure (239)Pu, (240)Pu, (241)Pu, (242)Pu and (244)Pu on the same AMS sputter target is a great simplification. We have obtained a first result on the global fallout value of (244)Pu/(239)Pu = (5.7 ± 1.0) × 10(-5) based on soil samples from Salzburg prefecture, Austria. Furthermore, we suggest using the (242)Pu/(240)Pu ratio as an estimate of the initial (241)Pu/(239)Pu ratio, which allows dating of the time of irradiation based solely on Pu isotopes. We have checked the validity of this estimate using literature data, simulations, and environmental samples from soil from the Salzburg prefecture (Austria), from the shut down Garigliano Nuclear Power Plant (Sessa Aurunca, Italy) and from the Irish Sea near the Sellafield nuclear facility. The maximum deviation of the estimated dates from the expected ages is 6 years, while relative dating of material from the same source seems to be possible with a precision of less than 2 years. Additional information carried by the minor plutonium isotopes may allow further improvements of the precision of the method. PMID:23565016

Steier, P; Hrnecek, E; Priller, A; Quinto, F; Srncik, M; Wallner, A; Wallner, G; Winkler, S

2013-01-01

270

Plutonium contamination in the environment. September 1977-November 1989 (A Bibliography from the Selected Water Resources Abstracts data base). Report for September 1977-November 1989  

SciTech Connect

This bibliography contains citations concerning the ecological impact of plutonium contamination in the environment. Topics include plutonium contamination in freshwater and marine sediments, plutonium bioaccumulation, plutonium transport in the food chain, plutonium contamination bioindicators, methods of analysis, plutonium genotoxicity, plutonium contamination in soil and groundwater, and plutonium contamination from nuclear fallout and nuclear facilities. Plutonium distribution changes due to stratification in oxic and anoxic environments are described. (Contains 83 citations fully indexed and including a title list.)

Not Available

1990-05-01

271

Estimation of plutonium in Hanford Site waste tanks based on historical records  

SciTech Connect

An estimation of plutonium in the Hanford Site waste storage tanks is important to nuclear criticality concerns. A reasonable approach for estimating the plutonium in the tanks can be established by considering the recovery efficiency of the chemical separation plants on the plutonium produced in the Hanford reactors. The waste loss from the separation processes represents the bulk of the plutonium in the waste tanks. The lesser contributor of plutonium to the waste tanks was the Plutonium Finishing Plant (PFP). When the PFP waste is added to the plutonium waste from separations, the result is the total estimated amount of plutonium discharged to the waste tanks at the Hanford Site. This estimate is for criticality concerns, and therefore is based on conservative assumptions (giving higher plutonium values). The estimate has been calculated to be {approx}981 kg of plutonium in the single- and double-shell high-level waste tanks.

Roetman, V.E.; Roblyer, S.P.; Toffer, H.

1994-09-01

272

Direct reduction of actinide oxide and carbide to metal: Application to the preparation of plutonium metal  

NASA Astrophysics Data System (ADS)

Three different conversion and refining methods for the preparation of high purity plutonium metal are described: the calciothermic reduction of plutonium oxide followed by electrorefining; the thoriothermic reduction of plutonium oxide followed by selective evaporation; the tantalothermic reduction of plutonium carbide followed by selective evaporation. The calciothermic reduction of plutonium oxide followed by electrorefining is used for the semi-industrial or large scale production of high purity plutonium metal. The rate and yield of preparation and refining is high. With high purity reactants the reduction of the oxide with thorium is well adapted to obtain high purity plutonium metal on the laboratory scale. The tantalothermic reduction of plutonium carbide gives high purity plutonium metal even with impure plutonium starting material (recovered from waste). This results from the high selectivity at the different steps of the process.

Spirlet, J. C.; Müller, W.; Van Audenhove, J.

1985-06-01

273

The mysterious world of plutonium metallurgy: Past and future  

SciTech Connect

The first atomic bomb detonated at the Trinity Site in New Mexico on July 16, 1945, used plutonium, a man-made element discovered < 5 yr earlier. The story of how Manhattan Project scientists and engineers tackled the mysteries of this element and fabricated it into the first atomic bomb is one of the most fascinating in the history of metallurgy and materials. The authors are currently trying to generate renewed interest in plutonium metallurgy because of the challenge posed by President Clinton, i.e., to keep the nuclear stockpile of weapons safe and reliable without nuclear testing. The stockpile stewardship challenge requires either a lifetime extension of the plutonium components or a remanufacture--neither of which can be verified by testing. In turn, this requires that one achieve a better fundamental understanding of plutonium. Of special interest is the effect of self-irradiation on the properties and on the long-term stability of plutonium and its alloys. Additional challenges arise from long-term concerns about disposing of plutonium and dealing with its environmental legacy. It is imperative to interest the next generation of students in these plutonium challenges.

Hecker, S.S.; Hammel, E.F. [Los Alamos National Lab., NM (United States)

1998-12-31

274

Plutonium recovery from spent reactor fuel by uranium displacement  

SciTech Connect

This report discusses a process for separating uranium values and transuranic values from fission products containing rare earth values when the values which are contained together in a molten chloride salt electrolyte. A molten chloride salt electrolyte with a first ratio of plutonium chloride to uranium chloride is contacted with both a solid cathode and an anode having values of uranium and fission products including plutonium. A voltage is applied across the anode and cathode electrolytically to transfer uranium and plutonium from the anode to the electrolyte while uranium values in the electrolyte electrolytically deposit as uranium metal on the solid cathode in an amount equal to the uranium and plutonium transferred from the anode causing the electrolyte to have a second ratio of plutonium chloride to uranium chloride. Then the solid cathode with the uranium metal deposited thereon is removed and molten cadmium having uranium dissolved therein is brought into contact with the electrolyte resulting in chemical transfer of plutonium values from the electrolyte to the molten cadmium and transfer of uranium values from the molten cadmium to the electrolyte until the first ratio of plutonium chloride to uranium chloride is re-established.

Ackerman, J.P.

1991-01-01

275

Kondo universality, energy scales, and intermediate valence in plutonium  

SciTech Connect

On the basis of the concepts of an intermediate-valence (IV) regime, an analysis is carried out of macroscopic properties of the {alpha} and {delta} phases of plutonium, as well as of several model systems based on rare earth elements. Within a single-site approximation (SSA), the characteristic Kondo interaction energy, the f-electron shell occupation number, the effective degeneracy of the ground-state f multiplet, and the crystal field splitting energy are estimated. The ground state in plutonium is considered as a quantum-mechanical superposition of states with different valences. The temperature dependence of the static magnetic susceptibility of {delta} plutonium is calculated. It is shown that {delta} plutonium satisfies the Wilson and Kadowaki-Woods universal relations, whereby it can be classified as a Kondo system. At the same time, the problem of the position of plutonium in the general classification of solids, as well as the problem of the temperature dependence of magnetic susceptibility of {delta} plutonium, remains open. The concept of multiple intermediate valence (MIV) is put forward as a possible means for solving the above problems. The MIV regime is characterized by fluctuations from the basic configuration 3+ to the states 4+ and 2+, which make a fundamental difference between plutonium and 4f electron systems based, say, on samarium.

Clementyev, E. S.; Mirmelstein, A. V., E-mail: mirmelstein@mail.r [Russian Federal Nuclear Center-Zababakhin Russian Research Institute of Technical Physics, Division of Experimental Physics (Russian Federation)

2009-07-15

276

Plutonium immobilization plant using glass in existing facilities at the Savannah River Site  

SciTech Connect

The Plutonium Immobilization Plant (PIP) accepts plutonium (Pu) from pit conversion and from non-pit sources and, through a glass immobilization process, converts the plutonium into an immobilized form that can be disposed of in a high level waste (HLW) repository. The objective is to make an immobilized form, suitable for geologic disposal, in which the plutonium is as inherently unattractive and inaccessible as the plutonium in spent fuel from commercial reactors.

DiSabatino, A., LLNL

1998-06-01

277

Plutonium and tritium produced in the Hanford Site production reactors  

SciTech Connect

In a news release on December 7, 1993, the Secretary of Energy announced declassification action that included totals for plutonium and tritium production in the Hanford Site production reactors. This information was reported as being preliminary because it was not fully supported by documentation. Subsequently, production data were made available from the US Department of Energy-Headquarters (DOE-HQ) records that indicated an increase of about one and one-half metric tons in total plutonium production. The Westinghouse Hanford Company was tasked by the US Department of Energy-Richland Operations Office to substantiate production figures and DOE-HQ data and to provide a defensible report of weapons- (6 wt% {sup 240}Pu) and nonweapons- (fuels-)grade (nominally 9 wt% or higher {sup 240}Pu) plutonium and tritium production in the Hanford Site production reactors. The task was divided into three parts. The first part was to determine plutonium and tritium production based on available reported accountability records. The second part was to determine plutonium production independently by calculational checks based on reactor thermal power generation and plutonium conversion factors representing the various reactor fuels. The third part was to resolve differences, if they occurred, in the reported and calculational results. In summary, the DOE-HQ-reported accountability records of plutonium and tritium production were determined to be the most defensible record of Hanford Site reactor production. The DOE-HQ records were consistently supported by the independent calculational checks and the records of operational data. Total production quantities are 67.4 MT total plutonium, which includes 12.9 MT of nonweapons-grade plutonium. The total tritium production was 10.6 kg.

Roblyer, S.P.

1994-09-28

278

Implementation impacts of PRL methodology. [PRL (Plutonium Recovery Limit)  

SciTech Connect

This report responds to a DOE-SR request to evaluate the impacts from implementation of the proposed Plutonium Recovery Limit (PRL) methodology. The PRL Methodology is based on cost minimization for decisions to discard or recover plutonium contained in scrap, residues, and other plutonium bearing materials. Implementation of the PRL methodology may result in decisions to declare as waste certain plutonium bearing materials originally considered to be a recoverable plutonium product. Such decisions may have regulatory impacts, because any material declared to be waste would immediately be subject to provisions of the Resource Conservation and Recovery Act (RCRA). The decision to discard these materials will have impacts on waste storage, treatment, and disposal facilities. Current plans for the de-inventory of plutonium processing facilities have identified certain materials as candidates for discard based upon the economic considerations associated with extending the operating schedules for recovery of the contained plutonium versus potential waste disposal costs. This report evaluates the impacts of discarding those materials as proposed by the F Area De-Inventory Plan and compares the De-Inventory Plan assessments with conclusions from application of the PRL. The impact analysis was performed for those materials proposed as potential candidates for discard by the De-Inventory Plan. The De-Inventory Plan identified 433 items, containing approximately 1% of the current SRS Pu-239 inventory, as not appropriate for recovery as the site moves to complete the mission of F-Canyon and FB-Line. The materials were entered into storage awaiting recovery as product under the Department's previous Economic Discard Limit (EDL) methodology which valued plutonium at its incremental cost of production in reactors. An application of Departmental PRLs to the subject 433 items revealed that approximately 40% of them would continue to be potentially recoverable as product plutonium.

Caudill, J.A.; Krupa, J.F.; Meadors, R.E.; Odum, J.V.; Rodrigues, G.C.

1993-02-01

279

Accelerator-based conversion (ABC) of reactor and weapons plutonium  

SciTech Connect

An accelerator-based conversion (ABC) system is presented that is capable of rapidly burning plutonium in a low-inventory sub-critical system. The system also returns fission power to the grid and transmutes troublesome long-lived fission products to short lived or stable products. Higher actinides are totally fissioned. The system is suited not only to controlled, rapid burning of excess weapons plutonium, but to the long range application of eliminating or drastically reducing the world total inventory of plutonium. Deployment of the system will require the successful resolution of a broad range of technical issues introduced in the paper.

Jensen, R.J.; Trapp, T.J.; Arthur, E.D.; Bowman, C.D.; Davidson, J.W.; Linford, R.K.

1993-06-01

280

Decision model for evaluating reactor disposition of excess plutonium  

SciTech Connect

The US Department of Energy is currently considering a range of technologies for disposition of excess weapon plutonium. Use of plutonium fuel in fission reactors to generate spent fuel is one class of technology options. This report describes the inputs and results of decision analyses conducted to evaluate four evolutionary/advanced and three existing fission reactor designs for plutonium disposition. The evaluation incorporates multiple objectives or decision criteria, and accounts for uncertainty. The purpose of the study is to identify important and discriminating decision criteria, and to identify combinations of value judgments and assumptions that tend to favor one reactor design over another.

Edmunds, T.

1995-02-01

281

Spiked Alloy Production for Accelerated Aging of Plutonium  

SciTech Connect

The accelerated aging effects on weapons grade plutonium alloys are being studied using {sup 238}Pu-enriched plutonium metal to increase the rate of formation of defect structures. Pyrochemical processing methods have been used to produce two {sup 238}Pu-spiked plutonium alloys with nominal compositions of 7.5 wt% {sup 238}Pu. Processes used in the preparation of the alloys include direct oxide reduction of PuO{sub 2} with calcium and electrorefining. Rolled disks were prepared from the spiked alloys for sampling. Test specimens were cut out of the disks for physical property measurements.

Wilk, P A; McNeese, J A; Dodson, K E; Williams, W L; Krikorian, O H; Blau, M S; Schmitz, J E; Bajao, F G; Mew, D A; Matz, T E; Torres, R A; Holck, D M; Moody, K J; Kenneally, J M

2009-07-10

282

Accelerator-driven assembly for plutonium transformation (ADAPT)  

SciTech Connect

A particle accelerator-driven spallation target and corresponding blanket region are proposed for the ultimate disposition of weapons-grade plutonium being retired from excess nuclear weapons in the US and Russia. The highly fissile plutonium is contained within .25 to .5 cm diameter silicon-carbide coated graphite beads, which are cooled by helium, within the slightly subcritical blanket region. Major advantages include very high one-pass burnup (over 90 %), a high integrity waste form (the coated beads), and operation in a subcritical mode, thereby minimizing the vulnerability to the positive reactivity feedbacks often associated with plutonium fuel.

Van Tuyle, G.J.; Todosow, M.; Powell, J.; Schweitzer, D.

1994-11-01

283

Gas pycnometry for density determination of plutonium parts  

SciTech Connect

The traditional method for plutonium density determination is by measuring the weight loss of the component when it is immersed in a liquid of known density, Archimedes` Principle. The most commonly used heavy liquids that are compatible for plutonium measurement are freon and monobromobenzene, but these pose serious environmental and health hazards. The contaminated liquid is also a radiological waste concern with difficult disposition. A gaseous medium would eliminate these environmental and health concerns. A collaborative research effort between the Savannah River Technology Center and Los Alamos National Laboratory was undertaken to determine the feasibility of a gaseous density measurement process for plutonium hemishells.

Collins, S.; Randolph, H.W.

1997-08-19

284

Plutonium Immobilization Can Loading FY98 Year End Design Report  

SciTech Connect

The Plutonium Immobilization Facility will immobilize plutonium in ceramic pucks and seal the pucks inside welded cans. Remote equipment will place these cans in magazines and the magazines in a Defense Waste Processing Facility (DWPF) canister. The DWPF will fill the canister with glass for permanent storage. This report summarizes FY98 Can Loading work completed for the Plutonium Immobilization Project and it includes summaries of reports on Can Size, Equipment Review, Preliminary Concepts, Conceptual Design, and Preliminary Specification. Plant trip reports for the Greenville Automation and Manufacturing Exposition, Rocky Flats BNFL Pu repackaging glovebox line, and vendor trips are also included.

Kriikku, E.

1998-11-25

285

Uranium and plutonium isotopes in the atmosphere  

SciTech Connect

Uranium 234 and 235 were found to be highly enriched relative to uranium 238 in several rain samples collected at Fayetteville, Arkansas, during the months of April and May 1980. The anomalous uranium appears to have originated from the Soviet satellite Cosmos-954, which fell over Canada on January 24, 1978. The uranium fallout occurred just about the time Mount St. Helens erupted on May 18, 1980. The concentration of /sup 238/U in rain increased markedly after the eruption of Mount St. Helens, and it appeared as if a large quantity of natural uranium was injected into the atmosphere by the volcanic eruption. The pattern of variation of the concentrations of uranium in rain after the eruption of Mount St. Helens was found to be similar to that of plutonium isotopes.

Sakuragi, Y.; Meason, J.L.; Kuroda, P.K.

1983-04-20

286

Development of a plutonium-239 recovery incinerator  

SciTech Connect

A Plutonium-239 Recovery Incinerator is being developed for the Savannah River Plant (SRP) to reduce the volume of solid glovebox waste and to allow recovery of Pu-239 from the waste. The process will also allow treatment of some waste materials that are not certifiable for disposal at the Waste Isolation Pilot Plant (WIPP). It will consist of two electrically heated combustion chambers (furnace and afterburner) and a dry filtration off-gas system. A unique feature of the process is that it uses pyrohydrolysis to produce an ash that is amenable to Pu recovery through nitric acid/HF dissolution. A series of thermogravimetric (TGA) analyses have been performed to characterize potential incinerator feed materials. A functioning furnace mockup was built and operated to demonstrate electrically-heated pyrohydrolysis operation. 8 refs., 4 figs.

Williams, S; Charlesworth, D L

1988-01-01

287

Developments in plutonium waste assay at AWE.  

PubMed

In 2002 a paper was presented at the 43rd Annual Meeting of the Institute of Nuclear Materials Management (INMM) on the assay of low level plutonium (Pu) in soft drummed waste (Miller 2002 INMM Ann. Meeting (Orlando, FL, 23-27 July 2002)). The technique described enabled the Atomic Weapons Establishment (AWE), at Aldermaston in the UK, to meet the stringent Low Level Waste Repository at Drigg (LLWRD) conditions for acceptance for the first time. However, it was initially applied to only low density waste streams because it relied on measuring the relatively low energy (60 keV) photon yield from Am-241 during growth. This paper reviews the results achieved when using the technique to assay over 10,000 waste packages and presents the case for extending the range of application to denser waste streams. PMID:19454791

Miller, T J

2009-06-01

288

Measurement and interpretation of plutonium spectra  

SciTech Connect

The atomic spectroscopic data available for plutonium are among the rickest of any in the periodic system. They include high-resolution grating and Fourier-transform spectra as well as extensive Zeeman and isotope-shift studies. We summarize the present status of the term analysis and cite the configurations that have been identified. A least-squares adjustment of a parametric Hamiltonian for configurations of both Pu I and Pu II has shown that almost all of the expected low levels are now known. The use of a model Hamiltonian applicable to both lanthanide and actinide atomic species has been applied to the low configurations of Pu I and Pu II making use of trends predicted by ab initio calculations. This same model has been used to describe the energy levels of Pu/sup 3 +/ in LaCl/sub 3/, and an extension has permitted preliminary calculations of the spectra of other valence states.

Blaise, J.; Fred, M.S.; Carnall, W.T.; Crosswhite, H.M.; Crosswhite, H.

1982-01-01

289

Thermophysical properties of coexistent phases of plutonium  

SciTech Connect

Plutonium is the element with the greatest number of allotropic phases. Thermally induced transformations between these phases are typically characterized by thermal hysteresis and incomplete phase reversion. With Ga substitutal in the lattice, low symmetry phases are replaced by a higher symmetry phase. However, the low temperature Martensitic phase transformation ({delta} {yields} {alpha}{prime}) in Ga stabilized {delta}-phase Pu is characterized by a region of thermal hysteresis which can reach 200 C in extent. These regions of thermal hysteresis offer a unique opportunity to study thermodynamics in inhomogeneous systems of coexistent phases. The results of thermophysical properties measured for samples of inhomogeneous unalloyed and Ga alloyed Pu will be discussed and compared with similar measurements of their single phase constituents.

Freibert, Franz J [Los Alamos National Laboratory; Mitchell, Jeremy N [Los Alamos National Laboratory; Saleh, Tarik A [Los Alamos National Laboratory; Schwartz, Dan S [Los Alamos National Laboratory

2009-01-01

290

Global plutonium management: A security option  

SciTech Connect

The US surplus plutonium disposition program was created to reduce the proliferation risk posed by the fissile material from thousands of retired nuclear weapons. The Department of Energy has decided to process its Put into a form as secure as Pu in civilian spent fuel. While implementation issues have been considered, a major one (Russian reciprocity) remains unresolved. Russia has made disposition action conditional on extracting the fuel value of its Pu but lacks the infrastructure to do so. Assistance in the construction of the required facilities would conflict with official US policy opposing the development of a Pu fuel cycle. The resulting stagnation provides impetus for a reevaluation of US nonproliferation objectives and Pu disposition options. A strategy for satisfying Russian fuel value concerns and reducing the proliferation risk posed by surplus weapons-grade plutonium (WGPu) is proposed. The effectiveness of material alteration (e.g., isotopic, chemical, etc.{hor_ellipsis}) at reducing the desire, ability and opportunity for proliferation is assessed. Virtually all the security benefits attainable by material processing can be obtained by immobilizing Pu in large unit size/mass monoliths without a radiation barrier. Russia would be allowed to extract the Pu at a future date for use as fuel in a verifiable manner. Remote tracking capability, if proven feasible, would further improve safeguarding capability. As an alternate approach, the US could compensate Russia for its Pu, allowing it to be disposed of or processed elsewhere. A market based method for pricing Pu is proposed. Surplus Pu could represent access to nuclear fuel at a fixed price at a future date. This position can be replicated in the uranium market and priced using derivative theory. The proposed strategy attempts to meet nonproliferation objectives by recognizing technical limitations and satisfying political constraints.

Sylvester, K.W.B.

1998-12-31

291

Magnesite disposal of carbon dioxide  

SciTech Connect

In this paper we report our progress on developing a method for carbon dioxide disposal whose purpose it is to maintain coal energy competitive even is environmental and political pressures will require a drastic reduction in carbon dioxide emissions. In contrast to most other methods, our approach is not aiming at a partial solution of the problem, or at buying time for phasing out fossil energy. Instead, its purpose is to obtain a complete and economic solution of the problem, and thus maintain access to the vast fossil energy reservoir. A successful development of this technology would guarantee energy availability for many centuries even if world economic growth the most optimistic estimates that have been put forward. Our approach differs from all others in that we are developing an industrial process which chemically binds the carbon dioxide in an exothermic reaction into a mineral carbonate that is thermodynamically stable and environmentally benign.

Lackner, K.S.; Butt, D.P.; Wendt, C.H.

1997-08-01

292

Molecular Structure of Carbon Dioxide  

NSDL National Science Digital Library

Carbon dioxide was first described in the 17th century by Jan Baptist van Helmont, a Belgium chemist. The chemical CO2 is released into the atmosphere when carbon-containing fossil fuels like oil, natural gas, and coal are burned in air. It is also produced by various microorganisms in fermentation and is breathed out by animals. Plants absorb carbon dioxide during photosynthesis, using both the carbon and the oxygen to construct carbohydrates. Every year the amount of CO2 in the atmosphere is increasing. CO2 build-up in the atmosphere is caused by deforestation, therefore reducing the number of trees available to absorb CO2. Excess CO2 in the environment causes Global Warming and the Greenhouse Effect. It is also toxic to humans since inhalation of large amounts of CO2 can cause suffocation. Some beverages, such as beer and sparkling wine contain carbon dioxide as a result of fermentation.

2002-08-15

293

Carbon Dioxide - Our Common "Enemy"  

NASA Technical Reports Server (NTRS)

Health effects of brief and prolonged exposure to carbon dioxide continue to be a concern for those of us who manage this pollutant in closed volumes, such as in spacecraft and submarines. In both examples, considerable resources are required to scrub the atmosphere to levels that are considered totally safe for maintenance of crew health and performance. Defining safe levels is not a simple task because of many confounding factors, including: lack of a robust database on human exposures, suspected significant variations in individual susceptibility, variations in the endpoints used to assess potentially adverse effects, the added effects of stress, and the fluid shifts associated with micro-gravity (astronauts only). In 2007 the National Research Council proposed revised Continuous Exposure Guidelines (CEGLs) and Emergency Exposure Guidelines (EEGLs) to the U.S. Navy. Similarly, in 2008 the NASA Toxicology Group, in cooperation with another subcommittee of the National Research Council, revised Spacecraft Maximum Allowable Concentrations (SMACs). In addition, a 1000-day exposure limit was set for long-duration spaceflights to celestial bodies. Herein we examine the rationale for the levels proposed to the U.S. Navy and compare this rationale with the one used by NASA to set its limits. We include a critical review of previous studies on the effects of exposure to carbon dioxide and attempt to dissect out the challenges associated with setting fully-defensible limits. We also describe recent experiences with management of carbon dioxide aboard the International Space Station with 13 persons aboard. This includes the tandem operations of the Russian Vozduk and the U.S. Carbon Dioxide Removal System. A third removal system is present while the station is docked to the Shuttle spacecraft, so our experience includes the lithium hydroxide system aboard Shuttle for the removal of carbon dioxide. We discuss strategies for highly-efficient, regenerable removal of carbon dioxide that could meet the 1000-day SMAC of 0.5%, which would apply to long-duration voyages to Mars.

James, John T.; Macatangay, Ariel

2009-01-01

294

Determination of Plutonium-Beryllium Source Strength by Manganese Activation.  

National Technical Information Service (NTIS)

In this study the manganese-sulfate-bath technique was used to determine the total neutron output of a Plutonium-Beryllium neutron source. Activation trials were conducted using 4 different concentrations of manganese sulfate and 3 different size containe...

P. F. Whitworth

1988-01-01

295

Adsorption of Neptunium and Plutonium on Metal Phosphites.  

National Technical Information Service (NTIS)

The removal of neptunium and plutonium from water by adsorption on titanium, zirconium, bismuth, thorium, and uranium phosphites was investigated. These phosphites hydrolyze in neutral or alkaline solution producing the hydrous metal oxides that are more ...

G. L. Silver

1979-01-01

296

Automated controlled-potential coulometer for plutonium determination  

SciTech Connect

The automated controlled-potential coulometer for the determination of plutonium described in this report is the second in a series of automated instruments designed to determine plutonium and uranium contents in nuclear fuel cycle materials. The measurement precision of the instrument is 0.1% relative standard deviation at the 5-mg plutonium level. A highly selective method of analysis was developed, involving reduction of plutonium to Pu(III) in a 5.5 M hydrochloric acid-0.015 M sulfamic acid electrolyte; oxidation of diverse ions, but not Pu(III); addition of phosphate complexant to reduce the Pu(III)-Pu(IV) potential; and oxidation of Pu(III) to Pu(IV) as the measurement step. Construction details of the mechanical and electrical systems of the instrument and control-system software are described, along with instrument preoperational adjustments and tests and sample analysis operations.

Hollen, R.M.; Jackson, D.D.

1981-05-01

297

Comparative behavior of americium and plutonium in wastewater  

SciTech Connect

This paper studies the behavior of trace americium and plutoniumin wastewater fed into purification systems. Activities of the elements were determined on a semiconductive alpha-ray spectrometer. the distributio nonuniformity, or heterogeneity, of americium and plutonium per unit volume of wastewater was determined quantitatively before and after passage through filter papers. The two elements were found to be in a colloidal or pseudocolloidal state in the original wastewater sample at pH 6. On acidifying the wastewater from pH 4 to 1 M nitric acid the americium passed quantitatively into the water phase but the most plutonium remained in the colloidal or pseudocolloidal state. the plutonium also passed quantitatively into the water phase in wastewater at a 1 M nitric acid acidity but only after a prolonged (12-day) hold. A knowledge of the heterogeneity of plutonium and americium in wastewaters made it possible to quickly distinguish their state, i.e., colloidal, pseudocolloidal, or in true solution.

Tsvetaeva, N.E.; Filin, V.M.; Ragimov, T.K.; Rudaya, L.Y.; Shapiro, K.Y.; Shcherbakov, B.Y.

1986-09-01

298

Handling, Storage, and Disposition of Plutonium and Uranium  

NASA Astrophysics Data System (ADS)

The need to address topics of handling, storage, and disposal of plutonium and uranium is driven by concern about hazards posed by the element and by the worldwide quantity of civilian and military materials. The projected inventory of separated civilian plutonium for use in fabricating mixed-oxide (MOX) reactor fuel during initial decades of this century is constant at about 120 metric tons and a comparable amount of excess military plutonium is anticipated from reductions in nuclear weapon stockpiles (IAEA Report, 1998). Although inventories of civilian material are in oxide form, Pu from weapons programs exists primarily as metal. Plutonium is a radiological toxin (Voelz, 2000); its management in a safe and secure manner is essential for protecting workers, the public, and the environment.

Haschke, John M.; Stakebake, Jerry L.

299

Factors Affecting Plant Absorption, Transport and Fate of Plutonium.  

National Technical Information Service (NTIS)

This study determined the extent to which several agricultural plants control plutonium (Pu) uptake and provides a general understanding of the fate and behavior of Pu in plants after absorption. Investigations were directed toward variables affecting the...

T. R. Garland, D. A. Cataldo, K. M. McFadden, R. E. Wildung

1984-01-01

300

Neutronic analysis of a proposed plutonium recycle assembly  

E-print Network

A method for the neutronic analysis of plutonium recycle assemblies has been developed with emphasis on relative power distribution prediction in the boundary area of vastly different spectral regions. Such regions are ...

Solan, George Michael

1975-01-01

301

Overview of Modeling and Simulations of Plutonium Aging  

SciTech Connect

Computer-aided materials research is now an integral part of science and technology. It becomes particularly valuable when comprehensive experimental investigations and materials testing are too costly, hazardous, or of excessive duration; then, theoretical and computational studies can supplement and enhance the information gained from limited experimental data. Such is the case for improving our fundamental understanding of the properties of aging plutonium in the nuclear weapons stockpile. The question of the effects of plutonium aging on the safety, security, and reliability of the nuclear weapons stockpile emerged after the United States closed its plutonium manufacturing facility in 1989 and decided to suspend any further underground testing of nuclear weapons in 1992. To address this, the Department of Energy's National Nuclear Security Administration (NNSA) initiated a research program to investigate plutonium aging, i.e., the changes with time of properties of Pu-Ga alloys employed in the nuclear weapons and to develop models describing these changes sufficiently reliable to forecast them for several decades. The November 26, 2006 press release by the NNSA summarizes the conclusions of the investigation, '...there appear to be no serious or sudden changes occurring, or expected to occur, in plutonium that would affect performance of pits beyond the well-understood, gradual degradation of plutonium materials'. Furthermore, 'These studies show that the degradation of plutonium in our nuclear weapons will not affect warhead reliability for decades', then NNSA Administrator Linton Brooks said. 'It is now clear that although plutonium aging contributes, other factors control the overall life expectancy of nuclear weapons systems'. The origin of plutonium aging is the natural decay of certain plutonium isotopes. Specifically, it is the process of alpha decay in which a plutonium atom spontaneously splits into a 5 MeV alpha particle and an 85keV uranium recoil. The alpha particle traverses the lattice, slowly loosing energy through electronic excitations, acquiring two electrons to become a helium atom, then finally coming to rest approximately 10 microns away with the generation of a few-hundred Frenkel pairs. The uranium recoil immediately displaces a couple-thousand Pu atoms from their original lattice sites. This process, which occurs at a rate of approximately 41 parts-per-million per year, is the source of potential property changes in aging plutonium. Plutonium aging encompasses many areas of research: radiation damage and radiation effects, diffusion of point defects, impurities and alloying elements, solid state phase transformations, dislocation dynamics and mechanical properties, equations of state under extreme pressures, as well as surface oxidation and corrosion. Theory, modeling, and computer simulations are involved to various degrees in many of these areas. The joint research program carried out at Lawrence Livermore National Laboratory and Los Alamos National Laboratory encompassed experimental measurements of numerous properties of newly fabricated reference alloys, archival material that have accumulated the effects of several decades of radioactive decay, and accelerated aging alloys in which the isotropic composition was adjusted to increase the rate of self-irradiation damage. In particular, the physical and chemical processes of nuclear materials degradation were to be studied individually and in great depth. Closely coupled to the experimental efforts are theory, modeling, and simulations. These efforts, validated by the experiments, aim to develop predictive models to evaluate the effects of age on the properties of plutonium. The need to obtain a scientific understanding of plutonium aging has revitalized fundamental research on actinides and plutonium in particular. For example, the experimental discovery of superconductivity in Pu-based compounds, the observation of helium bubbles in naturally aged material, and the measurement of phonon dispersion properties in gallium-stabilized delta plu

Schwartz, A J; Wolfer, W G

2007-04-24

302

Development of the Direct Fabrication Process for Plutonium Immobilization  

SciTech Connect

The current baseline process for fabricating pucks for the Plutonium Immobilization Program includes granulation of the milled feed prior to compaction. A direct fabrication process was demonstrated that eliminates the need for granulation.

Congdon, J.W.

2001-07-10

303

Seventh International Carbon Dioxide Conference  

NSDL National Science Digital Library

Organized by NOAA's Climate Monitoring and Diagnostic Laboratory (CMDL), the Seventh International Carbon Dioxide Conference is planned September 25-30 in Broomfield, Colo. At this website, scientists involved in various aspects of the global carbon cycle, especially the current increases of carbon dioxide in the atmosphere, are encouraged to attend. Users can read the preliminary announcement and can learn about the themes of the conference. Researchers can learn about abstract submissions and accommodations. The Brief Conference History link offers a nice synopsis of the accomplishments of past conferences.

304

Carbon Dioxide Absorption Heat Pump  

NASA Technical Reports Server (NTRS)

A carbon dioxide absorption heat pump cycle is disclosed using a high pressure stage and a super-critical cooling stage to provide a non-toxic system. Using carbon dioxide gas as the working fluid in the system, the present invention desorbs the CO2 from an absorbent and cools the gas in the super-critical state to deliver heat thereby. The cooled CO2 gas is then expanded thereby providing cooling and is returned to an absorber for further cycling. Strategic use of heat exchangers can increase the efficiency and performance of the system.

Jones, Jack A. (Inventor)

2002-01-01

305

Erbium diffusion in silicon dioxide  

SciTech Connect

Erbium diffusion in silicon dioxide layers prepared by magnetron sputtering, chemical vapor deposition, and thermal growth has been investigated by secondary ion mass spectrometry, and diffusion coefficients have been extracted from simulations based on Fick's second law of diffusion. Erbium diffusion in magnetron sputtered silicon dioxide from buried erbium distributions has in particular been studied, and in this case a simple Arrhenius law can describe the diffusivity with an activation energy of 5.3{+-}0.1 eV. Within a factor of two, the erbium diffusion coefficients at a given temperature are identical for all investigated matrices.

Lu Yingwei; Julsgaard, B.; Petersen, M. Christian [Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C (Denmark); Jensen, R. V. Skougaard [Department of Physics and Nanotechnology, Aalborg University, DK-9220 Aalborg O (Denmark); Pedersen, T. Garm; Pedersen, K. [Department of Physics and Nanotechnology, Aalborg University, DK-9220 Aalborg O (Denmark); Interdisciplinary Nanoscience Center-iNANO, DK-8000 Aarhus C (Denmark); Larsen, A. Nylandsted [Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C (Denmark); Interdisciplinary Nanoscience Center-iNANO, DK-8000 Aarhus C (Denmark)

2010-10-04

306

Enthalpies of dissociation of clathrate hydrates of carbon dioxide, nitrogen, (carbon dioxide + nitrogen), and (carbon dioxide + nitrogen + tetrahydrofuran)  

Microsoft Academic Search

A calorimetric technique is described for measuring the enthalpy of dissociation liberated from solid hydrates. In this study, the enthalpies of dissociation were determined at T= 273.65 K andp= 0.1 MPa for simple and mixed hydrates of carbon dioxide, nitrogen, (carbon dioxide + nitrogen), and (carbon dioxide + nitrogen + tetrahydrofuran) using an isothermal microcalorimeter. The addition of tetrahydrofuran (THF)

B.-J. Ryu

2001-01-01

307

Recovery of weapon plutonium as feed material for reactor fuel  

SciTech Connect

This report presents preliminary considerations for recovering and converting weapon plutonium from various US weapon forms into feed material for fabrication of reactor fuel elements. An ongoing DOE study addresses the disposition of excess weapon plutonium through its use as fuel for nuclear power reactors and subsequent disposal as spent fuel. The spent fuel would have characteristics similar to those of commercial power spent fuel and could be similarly disposed of in a geologic repository.

Armantrout, G.A.; Bronson, M.A.; Choi, Jor-Shan [and others

1994-03-16

308

Wastes from plutonium conversion and scrap recovery operations  

SciTech Connect

This report deals with the handling of defense-related wastes associated with plutonium processing. It first defines the different waste categories along with the techniques used to assess waste content. It then discusses the various treatment approaches used in recovering plutonium from scrap. Next, it addresses the various waste management approaches necessary to handle all wastes. Finally, there is a discussion of some future areas for processing with emphasis on waste reduction. 91 refs., 25 figs., 4 tabs.

Christensen, D.C.; Bowersox, D.F.; McKerley, B.J.; Nance, R.L.

1988-03-01

309

Handling, Storage, and Disposition of Plutonium and Uranium  

Microsoft Academic Search

\\u000a The need to address topics of handling, storage, and disposal of plutonium and uranium is driven by concern about hazards\\u000a posed by the element and by the worldwide quantity of civilian and military materials. The projected inventory of separated\\u000a civilian plutonium for use in fabricating mixed-oxide (MOX) reactor fuel during initial decades of this century is constant\\u000a at about 120

John M. Haschke; Jerry L. Stakebake

310

Handling, Storage, and Disposition of Plutonium and Uranium  

Microsoft Academic Search

The need to address topics of handling, storage, and disposal of plutonium and uranium is driven by concern about hazards\\u000a posed by the element and by the worldwide quantity of civilian and military materials. The projected inventory of separated\\u000a civilian plutonium for use in fabricating mixed-oxide (MOX) reactor fuel during initial decades of this century is constant\\u000a at about 120

John M. Haschke; Jerry L. Stakebake

311

Nondestructive assay of plutonium fuel for FFTF and supporting operations  

Microsoft Academic Search

Nondestructive assay (NDA) of plutonium fuel in connection with the Fast Flux Test Facility and supporting operations at the Hanford Engineering Development Laboratory is described. Plutonium materials associated with these operations include PuO2, mixed oxide powder and pellets, fast breeder reactor fuel pins and fuel bundles, solutions, dry scrap and waste. State-of-the-art NDA instruments utilized in safeguards and material control

P. Goris; G. B. Frandsen; G. P. Gottschalk; M. C. Lambert; J. A. Petty

1981-01-01

312

Optimization of solvent extraction cycles to separate plutonium and neptunium  

Microsoft Academic Search

This paper describes the steps taken to assess the potential of a solvent extraction process for separating plutonium from neptunium. The plutonium, namely ²³⁸Pu, is of importance because it is the isotope used in making radioisotope thermoelectric generators and radioisotope heaters and is obtained by irradiating ²³⁷Np targets in a high neutron flux environment. After the neptunium targets have been

D. L. Marsh; L. F. Miller; W. Bond; R. C. Martin; L. K. Felker; R. M. Wham; G. K. Schweitzer

1998-01-01

313

Optimization of solvent extraction cycles to separate plutonium and neptunium  

SciTech Connect

This paper describes the steps taken to assess the potential of a solvent extraction process for separating plutonium from neptunium. The plutonium, namely {sup 238}Pu, is of importance because it is the isotope used in making radioisotope thermoelectric generators and radioisotope heaters and is obtained by irradiating {sup 237}Np targets in a high neutron flux environment. After the neptunium targets have been irradiated, the targets could then be processed by solvent extraction methods.

Marsh, D.L.; Miller, L.F. [Univ. of Tennessee, Knoxville, TN (United States); Bond, W.; Martin, R.C.; Felker, L.K.; Wham, R.M. [Oak Ridge Y-12 Plant, TN (United States); Schweitzer, G.K. [Univ. of Tennessee, Knoxville, TN (United States)

1998-09-01

314

Evolving Metallurgical Behaviors in Plutonium from Self-Irradiation  

SciTech Connect

The plutonium alpha-decay leads to the age-related changes in physical properties. We review our experimental approaches including analytical techniques to assess the effects of extended aging on plutonium alloys, together with our recent results on age-related changes in physical and static mechanical properties. The ultimate goal of this work is to develop capabilities to predict metallurgical evolution driven by aging effects.

Chung, B W; Lema, K E; Hiromoto, D S

2009-05-05

315

Radiochemical determination of plutonium in glass fiber filters  

SciTech Connect

Multi-filter ambient air samples were analyzed to determine percent recovery and sensitivity at levels necessary for ambient air monitoring. The average percent recovery of plutonium-236 in ambient air samples using S and S glass fiber filters and analytical results for S and S glass fiber filters spiked with plutonium-239 at a concentration of 4.03 dis/min are tabulated.

Trice, C.

1984-06-12

316

Plutonium metal and oxide container weld development and qualification  

SciTech Connect

Welds were qualified for a container system to be used for long-term storage of plutonium metal and oxide. Inner and outer containers are formed of standard tubing with stamped end pieces gas-tungsten-arc (GTA) welded onto both ends. The weld qualification identified GTA parameters to produce a robust weld that meets the requirements of the Department of Energy standard DOE-STD-3013-94, ``Criteria for the Safe Storage of Plutonium Metals and Oxides.``

Fernandez, R.; Horrell, D.R.; Hoth, C.W.; Pierce, S.W.; Rink, N.A.; Rivera, Y.M.; Sandoval, V.D.

1996-01-01

317

Chinese strategic weapons and the plutonium option (U)  

SciTech Connect

In their article "Chinese Strategic Weapons and the Plutonium Option," John W. Lewis and Xue Litai of the Center for International Security and Arms Control at Stanford University's International Strategic Institute present an unclassified look at plutonium processing in the PRC. The article draws heavily on unclassified PRC sources for its short look at this important subject. Interested readers will find more detailed information in the recently available works referenced in the article.

Lewis, John W.; Xui Litai

1988-04-01

318

Bulging of cans containing plutonium residues. Summary report  

SciTech Connect

In 1994, two cans in the Lawrence Livermore National Laboratory Plutonium Facility were found to be bulging as a result of the generation of gases form the plutonium ash residues contained in the cans. This report describes the chronology of this discovery, the response actions that revealed other pressurized cans, the analysis of the causes, the short-term remedial action, a followup inspection of the short-term storage packages, and a review of proposed long-term remedial options.

Van Konynenburg, R.A.; Wood, D.H.; Condit, R.H.; Shikany, S.D.

1996-03-01

319

21 CFR 73.2575 - Titanium dioxide.  

Code of Federal Regulations, 2010 CFR

...specifications. The color additive titanium dioxide shall...restrictions. The color additive titanium dioxide may...consistent with good manufacturing practice. (c) Labeling...requirements. The color additive and any mixtures...

2010-04-01

320

Nitrogen dioxide, sulfur dioxide, and ammonia detector for remote sensing of vehicle emissions  

E-print Network

Nitrogen dioxide, sulfur dioxide, and ammonia detector for remote sensing of vehicle emissions monoxide, carbon dioxide, and exhaust hydrocarbons in the IR and nitric oxide in the UV. The design adds the capability to measure nitrogen dioxide in the UV with one spectrometer and to measure SO2 and NH3 along

Denver, University of

321

Decontamination of Battelle-Columbus' Plutonium Facility. Final report  

SciTech Connect

The Plutonium Laboratory, owned and operated by Battelle Memorial Institute's Columbus Division, was located in Battelle's Nuclear Sciences area near West Jefferson, Ohio, approximately 17 miles west of Columbus, Ohio. Originally built in 1960 for plutonium research and processing, the Plutonium Laboratory was enlarged in 1964 and again in 1967. With the termination of the Advanced Fuel Program in March, 1977, the decision was made to decommission the Plutonium Laboratory and to decontaminate the building for unrestricted use. Decontamination procedures began in January, 1978. All items which had come into contact with radioactivity from the plutonium operations were cleaned or disposed of through prescribed channels, maintaining procedures to ensure that D and D operations would pose no risk to the public, the environment, or the workers. The entire program was conducted under the cognizance of DOE's Chicago Operations Office. The building which housed the Plutonium Laboratory has now been decontaminated to levels allowing it to house ordinary laboratory and office operations. A ''Finding of No Significant Impact'' (FNSI) was issued in May, 1980.

Rudolph, A.; Kirsch, G.; Toy, H.L. (comps.)

1984-11-12

322

Carbon dioxide transport over complex terrain  

USGS Publications Warehouse

The nocturnal transport of carbon dioxide over complex terrain was investigated. The high carbon dioxide under very stable conditions flows to local low-ground. The regional drainage flow dominates the carbon dioxide transport at the 6 m above the ground and carbon dioxide was transported to the regional low ground. The results show that the local drainage flow was sensitive to turbulent mixing associated with local wind shear.

Sun, J.; Burns, S. P.; Delany, A. C.; Oncley, S. P.; Turnipseed, A.; Stephens, B.; Guenther, A.; Anderson, D. E.; Monson, R.

2004-01-01

323

Method and apparatus for producing chlorine dioxide  

Microsoft Academic Search

A continuous method and apparatus are described for the efficient production of gaseous chlorine dioxide by the reaction between gaseous sulfur dioxide and an aqueous solution of a metallic chlorate. The chlorate solution and a highly concentrated sulfur dioxide gas are introduced into a packed columnar chamber at closely adjacent locations at the bottom of the chamber so as to

P. W. Santillie; D. M. Ramras

1984-01-01

324

Electronic structure of silicon dioxide (a review)  

NASA Astrophysics Data System (ADS)

Silicon dioxide amorphous films are the key insulators in silicon integrated circuits. The physical properties of silicon dioxide are determined by the electronic structure of this material. The currently available information on the electronic structure of silicon dioxide has been systematized.

Nekrashevich, S. S.; Gritsenko, V. A.

2014-02-01

325

2, 18491865, 2005 Carbon dioxide in  

E-print Network

BGD 2, 1849­1865, 2005 Carbon dioxide in southern Poland L. Chmura et al. Title Page Abstract is licensed under a Creative Commons License. 1849 #12;BGD 2, 1849­1865, 2005 Carbon dioxide in southern urban environment with numerous local sources of carbon dioxide. Despite of relative proximity of those

Paris-Sud XI, Université de

326

SEISMIC MONITORING OF CARBON DIOXIDE FLUID FLOW  

E-print Network

SEISMIC MONITORING OF CARBON DIOXIDE FLUID FLOW J. E. Santos1, G. B. Savioli2, J. M. Carcione3, D´e, Argentina SEISMIC MONITORING OF CARBON DIOXIDE FLUID FLOW ­ p. #12;Introduction. I Storage of CO2). SEISMIC MONITORING OF CARBON DIOXIDE FLUID FLOW ­ p. #12;Introduction. II CO2 is separated from natural

Santos, Juan

327

SEISMIC MONITORING OF CARBON DIOXIDE FLUID FLOW  

E-print Network

SEISMIC MONITORING OF CARBON DIOXIDE FLUID FLOW J. E. Santos1 1 Department of Mathematics, Purdue University, USA Purdue University, March 1rst, 2013 SEISMIC MONITORING OF CARBON DIOXIDE FLUID FLOW ­ p. #12 (North Sea). SEISMIC MONITORING OF CARBON DIOXIDE FLUID FLOW ­ p. #12;Introduction. II CO2 is separated

Santos, Juan

328

7Carbon Dioxide Increases The Keeling Curve,  

E-print Network

7Carbon Dioxide Increases The Keeling Curve, shown to the left, shows the variation in concentration of atmospheric carbon dioxide since 1958-1974. It is based on continuous measurements taken of rapidly increasing carbon dioxide levels in the atmosphere. Additional measurements by scientists working

329

21 CFR 184.1240 - Carbon dioxide.  

...2014-04-01 2014-04-01 false Carbon dioxide. 184.1240 Section 184.1240 Food and Drugs...Substances Affirmed as GRAS § 184.1240 Carbon dioxide. (a) Carbon dioxide (empirical formula CO2 , CAS Reg. No....

2014-04-01

330

Conversion of Uranium Oxide into Nitrate with Nitrogen Dioxide  

Microsoft Academic Search

In order to decrease the amount of aqueous liquid waste discharged from nuclear fuel reprocessing, the conversion of uranium dioxide into its nitrate using liquefied nitrogen dioxide was studied. Uranium dioxide powder was immersed in liquefied nitrogen dioxide at 313 K after a pretreatment by the oxidation of the uranium dioxide with nitrogen dioxide and air at 523 K. Seventy-nine

Kayo Sawada; Daisuke Hirabayashi; Youichi Enokida; Ichiro Yamamoto

2008-01-01

331

Application of Prompt Gamma-Ray Analysis to Identify Electrorefining Salt-Bearing Plutonium Oxide at the Plutonium Finishing Plant  

Microsoft Academic Search

Prompt gamma-ray analysis is being implemented at the Plutonium Finishing Plant (PFP) to screen impure plutonium oxide inventory items, received in the mid-1980s from the Rocky Flats Plant, for the presence of sodium chloride and potassium chloride salts from the electrorefining process. A large fraction of these items are suspected to contain electrorefining salts. Because the salts evaporate at the=950C

Dennis M. Fazzari; Susan A. Jones; Calvin H. Delegard

2003-01-01

332

Geological storage of carbon dioxide  

Microsoft Academic Search

Carbon dioxide is the main compound identified as affecting the stability of the Earth's climate. A significant reduction in the volume of greenhouse gas emissions to the atmosphere is a key mechanism for mitigating against climate change. Geological storage of CO 2, or the injection and stabilization of large volumes of CO 2 in the subsurface in saline aquifers, existing

S. J. Baines; RICHARD H. WORDEN

2004-01-01

333

Sulfur Dioxide and Material Damage  

ERIC Educational Resources Information Center

This study relates sulfur dioxide levels with material damage in heavily populated or polluted areas. Estimates of loss were determined from increased maintenance and replacement costs. The data indicate a decrease in losses during the past five years probably due to decline in pollution levels established by air quality standards. (MR)

Gillette, Donald G.

1975-01-01

334

SULFUR DIOXIDE SOURCES IN AK  

EPA Science Inventory

This map shows industrial plants which emit 100 tons/year or more of sulfur dioxide (SO2) in Alaska. The SO2 sources are plotted on a background map of cities and county boundaries. Data Sources: SO2 Sites: U.S. EPA AIRS System, County Outlines: 1990 Census Tiger Line Files 1:1...

335

Reduction of worldwide plutonium inventories using conventional reactors and advanced fuels: A systems study  

SciTech Connect

The potential for reducing plutonium inventories in the civilian nuclear fuel cycle through recycle in LWRs of a variety of mixed-oxide forms is examined by means of a cost-based plutonium-flow systems model that includes an approximate measure of proliferation risk. The impact of plutonium recycle in a number of forms is examined, including the introduction of nonfertile fuels into conventional (LWR) reactors to reduce net plutonium generation, to increase plutonium burnup, and to reduce exo-reactor plutonium inventories.

Krakowski, R.A.; Bathke, C.G.; Chodak, P. III [Los Alamos National Lab., NM (United States). Technology and Safety Assessment Div.

1997-09-01

336

Benchmark Evaluation of Plutonium Nitrate Solution Arrays  

SciTech Connect

In October and November of 1981 thirteen approach-to-critical experiments were performed on a remote split table machine (RSTM) in the Critical Mass Laboratory of Pacific Northwest Laboratory (PNL) in Richland, Washington, using planar arrays of polyethylene bottles filled with plutonium (Pu) nitrate solution. Arrays of up to sixteen bottles were used to measure the critical number of bottles and critical array spacing with a tight fitting Plexiglas{reg_sign} reflector on all sides of the arrays except the top. Some experiments used Plexiglas shells fitted around each bottles to determine the effect of moderation on criticality. Each bottle contained approximately 2.4 L of Pu(NO3)4 solution with a Pu content of 105 g Pu/L and a free acid molarity H+ of 5.1. The plutonium was of low 240Pu (2.9 wt.%) content. These experiments were performed to fill a gap in experimental data regarding criticality limits for storing and handling arrays of Pu solution in reprocessing facilities. Of the thirteen approach-to-critical experiments eleven resulted in extrapolations to critical configurations. Four of the approaches were extrapolated to the critical number of bottles; these were not evaluated further due to the large uncertainty associated with the modeling of a fraction of a bottle. The remaining seven approaches were extrapolated to critical array spacing of 3-4 and 4-4 arrays; these seven critical configurations were evaluation for inclusion as acceptable benchmark experiments in the International Criticality Safety Benchmark Evaluation Project (ICSBEP) Handbook. Detailed and simple models of these configurations were created and the associated bias of these simplifications was determined to range from 0.00116 and 0.00162 {+-} 0.00006 ?keff. Monte Carlo analysis of all models was completed using MCNP5 with ENDF/BVII.0 neutron cross section libraries. A thorough uncertainty analysis of all critical, geometric, and material parameters was performed using parameter perturbation methods. It was found that uncertainty in the impurities in the polyethylene bottles, reflector position, bottle outer diameter, and critical array spacing had the largest effect. The total uncertainty ranged from 0.00651 to 0.00920 ?keff. Evaluation methods and results will be presented and discussed in greater detail in the full paper.

M. A. Marshall; J. D. Bess

2011-09-01

337

Application of Prompt Gamma-Ray Analysis to Identify Electrorefining Salt-Bearing Plutonium Oxide at the Plutonium Finishing Plant  

SciTech Connect

Prompt gamma-ray analysis is being implemented at the Plutonium Finishing Plant (PFP) to screen impure plutonium oxide inventory items, received in the mid-1980s from the Rocky Flats Plant, for the presence of sodium chloride and potassium chloride salts from the electrorefining process. A large fraction of these items are suspected to contain electrorefining salts. Because the salts evaporate at the=950C stabilization temperature mandated for long-term storage under the U.S. Department of Energy plutonium oxide stabilization and storage criteria to plug and corrode process equipment, items found to have these salts qualify for thermal stabilization at 750C. The prompt gamma ray energies characteristic of sodium, potassium, chlorine, and other low atomic weight elements arise from the interaction the light elements with alpha radiation from plutonium and americium radioactive decay. High-resolution gamma ray spectrometers designed to detect energies up to {approx}4.5 MeV are used to gather the high-energy prompt gamma spectra.Observation of the presence of the high-energy gamma peaks representing the natural chlorine-35, sodium-23, and potassium-39 isotopes and the sodium-to-chlorine peak area ratios in the range for plutonium oxide materials known to contain the electrorefining salts give the evidence needed to identify plutonium oxide materials at the PFP that qualify for the lower-temperature processing. Conversely, the absence of these telltale signals in the prompt gamma analysis provides evidence that the materials do not contain the electrorefining salts. Furthermore, based on calibrations using known assayed items, semiquantitative measurement of the quantity of chlorine present in materials containing electrorefining salt also can be performed by using the count rates observed for the chlorine peak, the plutonium quantity present in the measured item, and the plutonium- and chlorine-specific response of the gamma detection system. The origin and characteristics of the impure plutonium oxide, the process impacts of the electrorefining salts, and the background and technical bases of application of prompt gamma-ray analysis to identify electrorefining salt-bearing plutonium oxide at the PFP are described.

Fazzari, Dennis M. (FLUOR HANFORD, INC); Jones, Susan A. (FLUOR HANFORD, INC); Delegard, Calvin H. (BATTELLE (PACIFIC NW LAB))

2003-09-25

338

Plutonium solution analyzer. Revised February 1995  

SciTech Connect

A fully automated analyzer has been developed for plutonium solutions. It was assembled from several commercially available modules, is based upon segmented flow analysis, and exhibits precision about an order of magnitude better than commercial units (0.5%--0.05% RSD). The system was designed to accept unmeasured, untreated liquid samples in the concentration range 40--240 g/l: and produce a report with sample identification, sample concentrations, and an abundance of statistics. Optional hydraulics can accommodate samples in the concentration range 0.4--4.0 g/y. Operating at a typical rate of 30 to 40 samples per hour, it consumes only 0.074 ml of each sample and standard, and generates waste at the rate of about 1.5 ml per minute. No radioactive material passes through its multichannel peristaltic pump (which remains outside the glovebox, uncontaminated) but rather is handled by a 6-port, 2-position chromatography-type loop valve. An accompanying computer is programmed in QuickBASIC 4.5 to provide both instrument control and data reduction. The program is truly user-friendly and communication between operator and instrument is via computer screen displays and keyboard. Two important issues which have been addressed are waste minimization and operator safety (the analyzer can run in the absence of an operator, once its autosampler has been loaded).

Burns, D.A.

1995-02-01

339

PLUTONIUM LOADING CAPACITY OF REILLEX HPQ ANION EXCHANGE COLUMN - AFS-2 PLUTONIUM FLOWSHEET FOR MOX  

SciTech Connect

Radioactive plutonium (Pu) anion exchange column experiments using scaled HB-Line designs were performed to investigate the dependence of column loading performance on the feed composition in the H-Canyon dissolution process for plutonium oxide (PuO{sub 2}) product shipped to the Mixed Oxide (MOX) Fuel Fabrication Facility (MFFF). These loading experiments show that a representative feed solution containing {approx}5 g Pu/L can be loaded onto Reillex{trademark} HPQ resin from solutions containing 8 M total nitrate and 0.1 M KF provided that the F is complexed with Al to an [Al]/[F] molar ratio range of 1.5-2.0. Lower concentrations of total nitrate and [Al]/[F] molar ratios may still have acceptable performance but were not tested in this study. Loading and washing Pu losses should be relatively low (<1%) for resin loading of up to 60 g Pu/L. Loading above 60 g Pu/L resin is possible, but Pu wash losses will increase such that 10-20% of the additional Pu fed may not be retained by the resin as the resin loading approaches 80 g Pu/L resin.

Kyser, E.; King, W.; O'Rourke, P.

2012-07-26

340

A Novel Methodology for Processing of Plutonium-Bearing Waste as Ammonium Plutonium(III)-Oxalate  

SciTech Connect

A novel methodology has been developed for the recovery of Pu from different types of waste solutions generated during various operations involved in the chemical quality control/assurance of nuclear fuels. The method is based on the precipitation of Pu as ammonium plutonium(III)-oxalate and involves the adjustment of acidity of the Pu solution to 1 N, the addition of ascorbic acid (0.05 M) to reduce Pu to Pu(III), followed by the addition of (NH{sub 4}){sub 2}SO{sub 4} (0.5 M) and a stoichiometric amount of saturated oxalic acid maintaining a 0.2 M excess of oxalic acid concentration in the supernatant. The precipitate was characterized by X-ray powder diffraction and thermal and chemical analysis and was found to have the composition NH{sub 4}Pu(C{sub 2}O{sub 4}){sub 2}.3H{sub 2}O. This compound can be easily decomposed to PuO{sub 2} on heating in air at 823 K. Decontamination factors of U, Fe, and Cr determined showed quantitative removal of these ions during the precipitation of Pu as ammonium plutonium(III)-oxalate.A semiautomatic assembly based on the transfer of solutions by suction arrangement was designed and fabricated for processing large volumes of Pu solution. This assembly reduced the corrosion of the glove-box material and offered the advantage of lower radiation exposure to the working personnel.

Sali, Sanjay Krishnarao; Noronha, Donal Marshal; Mhatre, Hemakant Ramkrishna; Mahajan, Murlidhar Anna; Chander, Keshav; Aggarwal, Suresh Kumar; Venugopal, Venkatarama [Bhabha Atomic Research Centre (India)

2005-09-15

341

Solubility of Plutonium (IV) Oxalate During Americium/Curium Pretreatment  

SciTech Connect

Approximately 15,000 L of solution containing isotopes of americium and curium (Am/Cm) will undergo stabilization by vitrification at the Savannah River Site (SRS). Prior to vitrification, an in-tank pretreatment will be used to remove metal impurities from the solution using an oxalate precipitation process. Material balance calculations for this process, based on solubility data in pure nitric acid, predict approximately 80 percent of the plutonium in the solution will be lost to waste. Due to the uncertainty associated with the plutonium losses during processing, solubility experiments were performed to measure the recovery of plutonium during pretreatment and a subsequent precipitation process to prepare a slurry feed for a batch melter. A good estimate of the plutonium content of the glass is required for planning the shipment of the vitrified Am/Cm product to Oak Ridge National Laboratory (ORNL).The plutonium solubility in the oxalate precipitation supernate during pretreatment was 10 mg/mL at 35 degrees C. In two subsequent washes with a 0.25M oxalic acid/0.5M nitric acid solution, the solubility dropped to less than 5 mg/mL. During the precipitation and washing steps, lanthanide fission products in the solution were mostly insoluble. Uranium, and alkali, alkaline earth, and transition metal impurities were soluble as expected. An elemental material balance for plutonium showed that greater than 94 percent of the plutonium was recovered in the dissolved precipitate. The recovery of the lanthanide elements was generally 94 percent or higher except for the more soluble lanthanum. The recovery of soluble metal impurities from the precipitate slurry ranged from 15 to 22 percent. Theoretically, 16 percent of the soluble oxalates should have been present in the dissolved slurry based on the dilution effects and volumes of supernate and wash solutions removed. A trace level material balance showed greater than 97 percent recovery of americium-241 (from the beta dec ay of plutonium-241) in the dissolved precipitate, a value consistent with the recovery of europium, the americium surrogate.In a subsequent experiment, the plutonium solubility following an oxalate precipitation to simulate the preparation of a slurry feed for a batch melter was 21 mg/mL at 35 degrees C. The increase in solubility compared to the value measured during the pretreatment experiment was attributed to the increased nitrate concentration and ensuing increase in plutonium complexation. The solubility of the plutonium following a precipitant wash with 0.1M oxalic acid was unchanged. The recovery of plutonium from the precipitate slurry was greater than 97 percent allowing an estimation that approximately 92 percent of the plutonium in Tank 17.1 will report to the glass. The behavior of the lanthanides and soluble metal impurities was consistent with the behavior seen during the pretreatment experiment. A trace level material balance showed that 99.9 percent of the americium w as recovered from the precipitate slurry. The overall recovery of americium from the pretreatment and feed preparation processes was greater than 97 percent, which was consistent with the measured recovery of the europium surrogate.

Rudisill, T.S.

1999-08-11

342

1. West facade of Plutonium Concentration Facility (Building 233S), ReductionOxidation ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. West facade of Plutonium Concentration Facility (Building 233-S), Reduction-Oxidation Building (REDOX-202-S) to the right. Looking east. - Reduction-Oxidation Complex, Plutonium Concentration Facility, 200 West Area, Richland, Benton County, WA

343

Amarillo National Resource Center for Plutonium. Quarterly technical progress report, February 1, 1998--April 30, 1998  

SciTech Connect

Activities from the Amarillo National Resource Center for Plutonium are described. Areas of work include materials science of nuclear and explosive materials, plutonium processing and handling, robotics, and storage.

NONE

1998-06-01

344

Amarillo National Resource Center for Plutonium. Quarterly technical progress report, May 1, 1997--July 31, 1997  

SciTech Connect

Progress summaries are provided from the Amarillo National Center for Plutonium. Programs include the plutonium information resource center, environment, public health, and safety, education and training, nuclear and other material studies.

NONE

1997-09-01

345

Behavior of plutonium and americium at liquid cadmium cathode in molten LiCl-KCl electrolyte  

NASA Astrophysics Data System (ADS)

The effects of the electrochemical conditions on the behavior of plutonium and proper conditions for plutonium recovery at the liquid cadmium cathode (LCC) used in the pyrometallurgical reprocessing were studied by the electrotransport experiments with small, not stirred electrodes. Plutonium was successfully collected up to 7.75 wt% without disturbance by solid phase formation at the surface. Plutonium collected beyond saturation formed intermetallic compound PuCd 6 and accumulated at the bottom of the LCC. The cathodic current density adequate for plutonium collection was proportional to the concentration of plutonium in the molten salt. The behavior of americium was reasonably explained by a local equilibrium model between plutonium and americium at the surface of the LCC, although thermodynamic study and quantitative analysis are needed for further understanding. The plutonium collection rate in practical electrorefiner was estimated to be 324 g/h for one LCC by extrapolation of the experimental results.

Iizuka, Masatoshi; Uozumi, Koich; Inoue, Tadashi; Iwai, Takashi; Shirai, Osamu; Arai, Yasuo

2001-10-01

346

Reduction of Worldwide Plutonium Inventories Using Conventional Reactors and Advanced Fuels: A Systems Study  

SciTech Connect

The potential for reducing plutonium inventories in the civilian nuclear fuel cycle through recycle in LWRs of a variety of mixed oxide forms is examined by means of a cost based plutonium flow systems model. This model emphasizes: (1) the minimization of separated plutonium; (2) the long term reduction of spent fuel plutonium; (3) the optimum utilization of uranium resources; and (4) the reduction of (relative) proliferation risks. This parametric systems study utilizes a globally aggregated, long term (approx. 100 years) nuclear energy model that interprets scenario consequences in terms of material inventories, energy costs, and relative proliferation risks associated with the civilian fuel cycle. The impact of introducing nonfertile fuels (NFF,e.g., plutonium oxide in an oxide matrix that contains no uranium) into conventional (LWR) reactors to reduce net plutonium generation, to increase plutonium burnup, and to reduce exo- reactor plutonium inventories also is examined.

Krakowski, R.A., Bathke, C.G.

1997-12-31

347

PLUTONIUM/HIGH-LEVEL VITRIFIED WASTE BDBE DOSE CALCULATION  

SciTech Connect

The purpose of this calculation is to provide a dose consequence analysis of high-level waste (HLW) consisting of plutonium immobilized in vitrified HLW to be handled at the proposed Monitored Geologic Repository at Yucca Mountain for a beyond design basis event (BDBE) under expected conditions using best estimate values for each calculation parameter. In addition to the dose calculation, a plutonium respirable particle size for dose calculation use is derived. The current concept for this waste form is plutonium disks enclosed in cans immobilized in canisters of vitrified HLW (i.e., glass). The plutonium inventory at risk used for this calculation is selected from Plutonium Immobilization Project Input for Yucca Mountain Total Systems Performance Assessment (Shaw 1999). The BDBE examined in this calculation is a nonmechanistic initiating event and the sequence of events that follow to cause a radiological release. This analysis will provide the radiological releases and dose consequences for a postulated BDBE. Results may be considered in other analyses to determine or modify the safety classification and quality assurance level of repository structures, systems, and components. This calculation uses best available technical information because the BDBE frequency is very low (i.e., less than 1.0E-6 events/year) and is not required for License Application for the Monitored Geologic Repository. The results of this calculation will not be used as part of a licensing or design basis.

J.A. Ziegler

2000-11-20

348

DEMOLITION OF HANFORDS 233-S PLUTONIUM CONCENTRATION FACILITY  

SciTech Connect

This paper describes the technical approach being used to demolish a plutonium-contaminated processing facility at the Hanford Site. This project represents the first open-air demolition of a highly-contaminated plutonium facility at the Hanford Site. This project may also represent one of the first plutonium facilities in the DOE complex to be demolished without first decontaminating surfaces to near ''free release'' standards. Demolition of plutonium contamination structures, if not properly managed, can subject cleanup personnel and the environment to significant risk. However, with proper sequencing and innovative use of commercially-available equipment, materials, and services, this project is demonstrating that a plutonium processing facility can be demolished while avoiding the need to perform extensive decontamination or construct large enclosures. The project is utilizing an excavator with purpose-built concrete shears, diamond circular saws, water misting and fogging equipment, specialized fixatives and dust suppressant mixtures, conventional mobile crane and rigging services, and near real-time modeling of meteorological and radiological conditions. Between the months of October and December 2003, approximately 85 percent of the footprint of the 233-S Facility had been demolished and properly disposed. Demolition of the remaining and more technically-challenging portion of the facility is expected to be completed by April 2004.

BERLIN, G.T.

2004-01-21

349

Recovery of americium-241 from aged plutonium metal  

SciTech Connect

About 5 kg of ingrown /sup 241/Am was recovered from 850 kg of aged plutonium using a process developed specifically for Savannah River Plant application. The aged plutonium metal was first dissolved in sulfamic acid. Sodium nitrite was added to oxidize the plutonium to Pu(IV) and the residual sulfamate ion was oxidized to nitrogen gas and sulfate. The plutonium and americium were separated by one cycle of solvent extraction. The recovered products were subsequently purified by cation exchange chromatography, precipitated as oxalates, and calcined to the oxides. Plutonium processng was routine. Before cation exchange purification, the aqueous americium solution from solvent extraction was concentrated and stripped of nitric acid. More than 98% of the /sup 241/Am was then recovered from the cation exchange column where it was effectively decontaminated from all major impurities except nickel and chromium. This partially purified product solution was concentrated further by evaporation and then denitrated by reaction with formic acid. Individual batches of americium oxalate were then precipitated, filtered, washed, and calcined. About 98.5% of the americium was recovered. The final product purity averaged 98% /sup 241/AmO/sub 2/; residual impurities were primarily lead and nickel.

Gray, L.W.; Burney, G.A.; Reilly, T.A.; Wilson, T.W.; McKibben, J.M.

1980-12-01

350

Plutonium Immobilization Project (PIP) Precursor Material Calcine Temperature  

SciTech Connect

As a result of the end of the Cold War, approximately 50 metric tons of plutonium are no longer needed and have been identified for disposition. A ceramic waste form is the chosen option for immobilization of the excess plutonium. The plutonium ceramic form then will be encased in high-level waste glass using can-in-canister technology for final disposition. The precursor materials are the non-radioactive components that are added to the plutonium feed stream to form the desired phases in the immobilization product. The precursor materials are blended and calcined prior to being mixed with the plutonium feed stream. The purpose of the calcine step is to remove any physical or chemical water retained in the precursors and convert any hydroxides or carbonates to the oxides. Initially, a temperature of 750 degrees C for a period of one hour was chosen for the calcining of the precursors. In this effort, several different calcine temperatures were investigated to evaluate the effect on initial phase formation (in the calcined precursors), thermal expansion of the pressed pellets during heating, and mineralogy and porosity of the final product.

Cozzi, A.D.

1999-07-29

351

Chloride-catalyzed corrosion of plutonium in glovebox atmospheres  

SciTech Connect

Characterization of glovebox atmospheres and the black reaction product formed on plutonium surfaces shows that the abnormally rapid corrosion of components in the fabrication line is consistent with a complex salt-catalyzed reaction involving gaseous hydrogen chloride (HCl) and water. Analytical data verify that chlorocarbon and HCl vapors are presented in stagnant glovebox atmospheres. Hydrogen chloride concentrations approach 7 ppm at some locations in the glovebox line. The black corrosion product is identified as plutonium monoxide monohydride (PuOH), a product formed by hydrolysis of plutonium in liquid water and salt solutions at room temperature. Plutonium trichloride (PuCl{sub 3}) produced by reaction of HCl at the metal surface is deliquescent and apparently forms a highly concentrated salt solution by absorbing moisture from the glovebox atmosphere. Rapid corrosion is attributed to the ensuing salt-catalyzed reaction between plutonium and water. Experimental results are discussed, possible involvement of hydrogen fluoride (HF) is examined, and methods of corrective action are presented in this report.

Burgess, M. [ed.; Haschke, J.M.; Allen, T.H.; Morales, L.A.; Jarboe, D.M.; Puglisi, C.V.

1998-04-01

352

Oxygen and carbon dioxide sensing  

NASA Technical Reports Server (NTRS)

A high electron mobility transistor (HEMT) capable of performing as a CO.sub.2 or O.sub.2 sensor is disclosed, hi one implementation, a polymer solar cell can be connected to the HEMT for use in an infrared detection system. In a second implementation, a selective recognition layer can be provided on a gate region of the HEMT. For carbon dioxide sensing, the selective recognition layer can be, in one example, PEI/starch. For oxygen sensing, the selective recognition layer can be, in one example, indium zinc oxide (IZO). In one application, the HEMTs can be used for the detection of carbon dioxide and oxygen in exhaled breath or blood.

Ren, Fan (Inventor); Pearton, Stephen John (Inventor)

2012-01-01

353

Molecular Structure of Nitrogen dioxide  

NSDL National Science Digital Library

Nitrogen dioxide is a brown gas that readily dimerizes at lower temperatures to form the colorless gas dinitrogen trioxide. It is a byproduct of combustion that pollutes air and its gives smog its characteristic brown color. When gasoline, diesel fuel, or coal is burned at high temperatures nitric oxide (NO) is formed. Nitric oxide reacts slowly with oxygen to form nitrogen dioxide, or it can react with many organic-oxygen containing radicals (e.g., alkoxy and peroxy radicals) found in the atmosphere (also products of combustion) to more rapidly form NO2. The photolysis of NO2 by sunlight is the only known source of ozone to the troposphere (the layer of atmosphere closest to the earth); ozone is one of the most toxic components of smog and adversely affects human, animal and plant health in densely populated polluted regions.

2002-09-11

354

Sonochemical reduction of carbon dioxide  

Microsoft Academic Search

Sonolysis of carbon dioxide dissolved in water was performed from a standpoint of reducing this material in atmosphere. During one hour of sonication, the amount of CO2 decreased to about half at 5°C under CO2–Ar atmosphere. The decreasing rate for CO2 followed the order Ar>He>H2>N2 and it was down with increasing temperature in the range of 5–45°C. The most favorable

Hisashi Harada

1998-01-01

355

Nongovernmental valorization of carbon dioxide  

Microsoft Academic Search

Carbon dioxide (CO2) is considered the largest contributor to the greenhouse gas effect. Most attempts to manage the flow of CO2 or carbon into our environment involve reducing net emissions or sequestering the gas into long-lived sinks. Using CO2 as a chemical feedstock has a long history, but using it on scales that might impact the net emissions of CO2

Gene Petersen; Donn Viviani; Kim Magrini-Bair; Stephen Kelley; Luc Moens; Phil Shepherd; Dan DuBois

2005-01-01

356

Interpreting recent carbon dioxide data  

NSDL National Science Digital Library

Using web-accessed climate data, students will examine the latitudinal distribution of CO2 and explain how (and why) that has changed over (recent) time. They will then work in groups of two or three to download, graph, and interpret carbon dioxide concentration data from one individual location (different groups will be assigned a different site). Each student will complete a series of questions to ensure their understanding of the concepts outlined above.

Gordon, Elizabeth

357

Photoinduced reactivity of titanium dioxide  

Microsoft Academic Search

The utilization of solar irradiation to supply energy or to initiate chemical reactions is already an established idea. If a wide-band gap semiconductor like titanium dioxide (TiO2) is irradiated with light, excited electron–hole pairs result that can be applied in solar cells to generate electricity or in chemical processes to create or degrade specific compounds. Recently, a new process used

O. Carp; C. L. Huisman; A. Reller

2004-01-01

358

Weapons Grade Plutonium Destruction In The Gas Turbine Modular Helium Reactor (GT-MHR)  

Microsoft Academic Search

\\u000a The Gas Turbine Modular Helium Reactor (GT-MHR), when fueled with surplus weapons grade plutonium, has the unique capability\\u000a to destroy 90% of the initially charged plutonium-239 and 65% of the intitially charged total plutonium in a once through\\u000a reactor cycle while generating electricity at plant efficiencies of nearly 50%. The plutonium content and quality in the spent\\u000a fuel is so

David Alberstein

359

A probabilistic risk assessment of the LLNL Plutonium facility`s evaluation basis fire operational accident  

SciTech Connect

The Lawrence Livermore National Laboratory (LLNL) Plutonium Facility conducts numerous involving plutonium to include device fabrication, development of fabrication techniques, metallurgy research, and laser isotope separation. A Safety Analysis Report (SAR) for the building 332 Plutonium Facility was completed rational safety and acceptable risk to employees, the public, government property, and the environment. This paper outlines the PRA analysis of the Evaluation Basis Fire (EDF) operational accident. The EBF postulates the worst-case programmatic impact event for the Plutonium Facility.

Brumburgh, G.

1994-08-31

360

Carbon Dioxide Removal via Passive Thermal Approaches  

NASA Technical Reports Server (NTRS)

A paper describes a regenerable approach to separate carbon dioxide from other cabin gases by means of cooling until the carbon dioxide forms carbon dioxide ice on the walls of the physical device. Currently, NASA space vehicles remove carbon dioxide by reaction with lithium hydroxide (LiOH) or by adsorption to an amine, a zeolite, or other sorbent. Use of lithium hydroxide, though reliable and well-understood, requires significant mass for all but the shortest missions in the form of lithium hydroxide pellets, because the reaction of carbon dioxide with lithium hydroxide is essentially irreversible. This approach is regenerable, uses less power than other historical approaches, and it is almost entirely passive, so it is more economical to operate and potentially maintenance- free for long-duration missions. In carbon dioxide removal mode, this approach passes a bone-dry stream of crew cabin atmospheric gas through a metal channel in thermal contact with a radiator. The radiator is pointed to reject thermal loads only to space. Within the channel, the working stream is cooled to the sublimation temperature of carbon dioxide at the prevailing cabin pressure, leading to formation of carbon dioxide ice on the channel walls. After a prescribed time or accumulation of carbon dioxide ice, for regeneration of the device, the channel is closed off from the crew cabin and the carbon dioxide ice is sublimed and either vented to the environment or accumulated for recovery of oxygen in a fully regenerative life support system.

Lawson, Michael; Hanford, Anthony; Conger, Bruce; Anderson, Molly

2011-01-01

361

Ultraslow Wave Nuclear Burning of Uranium-Plutonium Fissile Medium on Epithermal Neutrons  

E-print Network

For a fissile medium, originally consisting of uranium-238, the investigation of fulfillment of the wave burning criterion in a wide range of neutron energies is conducted for the first time, and a possibility of wave nuclear burning not only in the region of fast neutrons, but also for cold, epithermal and resonance ones is discovered for the first time. For the first time the results of the investigation of the Feoktistov criterion fulfillment for a fissile medium, originally consisting of uranium-238 dioxide with enrichments 4.38%, 2.00%, 1.00%, 0.71% and 0.50% with respect to uranium-235, in the region of neutron energies 0.015-10.0eV are presented. These results indicate a possibility of ultraslow wave neutron-nuclear burning mode realization in the uranium-plutonium media, originally (before the wave initiation by external neutron source) having enrichments with respect to uranium-235, corresponding to the subcritical state, in the regions of cold, thermal, epithermal and resonance neutrons. In order to validate the conclusions, based on the slow wave neutron-nuclear burning criterion fulfillment depending on the neutron energy, the numerical modeling of ultraslow wave neutron-nuclear burning of a natural uranium in the epithermal region of neutron energies (0.1-7.0eV) was conducted for the first time. The presented simulated results indicate the realization of the ultraslow wave neutron-nuclear burning of the natural uranium for the epithermal neutrons.

V. D. Rusov; V. A. Tarasov; M. V. Eingorn; S. A. Chernezhenko; A. A. Kakaev; V. M. Vashchenko; M. E. Beglaryan

2014-09-25

362

Ultraslow Wave Nuclear Burning of Uranium-Plutonium Fissile Medium on Epithermal Neutrons  

E-print Network

For a fissile medium, originally consisting of uranium-238, the investigation of fulfillment of the wave burning criterion in a wide range of neutron energies is conducted for the first time, and a possibility of wave nuclear burning not only in the region of fast neutrons, but also for cold, epithermal and resonance ones is discovered for the first time. For the first time the results of the investigation of the Feoktistov criterion fulfillment for a fissile medium, originally consisting of uranium-238 dioxide with enrichments 4.38%, 2.00%, 1.00%, 0.71% and 0.50% with respect to uranium-235, in the region of neutron energies 0.015-10.0eV are presented. These results indicate a possibility of ultraslow wave neutron-nuclear burning mode realization in the uranium-plutonium media, originally (before the wave initiation by external neutron source) having enrichments with respect to uranium-235, corresponding to the subcritical state, in the regions of cold, thermal, epithermal and resonance neutrons. In order to...

Rusov, V D; Eingorn, M V; Chernezhenko, S A; Kakaev, A A

2014-01-01

363

Application of molten salt oxidation for the minimization and recovery of plutonium-238 contaminated wastes  

SciTech Connect

This paper presents the technical and economic feasibility of molten salt oxidation technology as a volume reduction and recovery process for {sup 238}Pu contaminated waste. Combustible low-level waste material contaminated with {sup 238}Pu residue is destroyed by oxidation in a 900 C molten salt reaction vessel. The combustible waste is destroyed creating carbon dioxide and steam and a small amount of ash and insoluble {sup 2328}Pu in the spent salt. The valuable {sup 238}Pu is recycled using aqueous recovery techniques. Experimental test results for this technology indicate a plutonium recovery efficiency of 99%. Molten salt oxidation stabilizes the waste converting it to a non-combustible waste. Thus installation and use of molten salt oxidation technology will substantially reduce the volume of {sup 238}Pu contaminated waste. Cost-effectiveness evaluations of molten salt oxidation indicate a significant cost savings when compared to the present plans to package, or re-package, certify and transport these wastes to the Waste Isolation Pilot Plant for permanent disposal. Clear and distinct cost advantages exist for MSO when the monetary value of the recovered {sup 238}Pu is considered.

Wishau, R.; Ramsey, K.B.; Montoya, A.

1998-12-31

364

CSER 96-027: storage of cemented plutonium residue containers in 55 gallon drums  

SciTech Connect

A nuclear criticality safety analysis has been performed for the storage of residual plutonium cementation containers, produced at the Plutonium Finishing Plant, in 55 gallon drums. This CSER increases the limit of total plutonium stored in each 55 gallon drum from 100 to 200 grams.

Watson, W.T.

1997-01-20

365

Dose Rates from Plutonium Metal and Beryllium Metal in a 9975 Shipping Container  

Microsoft Academic Search

A parametric study was performed of the radiation dose rates that might be produced if plutonium metal and beryllium metal were shipped in the 9975 shipping package. These materials consist of heterogeneous combinations plutonium metal and beryllium. The plutonium metal content varies up to 4.4 kilograms while the beryllium metal varies up to 4 kilograms. This paper presents the results

Nathan

2002-01-01

366

Concentrations and spatial distribution of plutonium in the terrestrial environment of the Marshall Islands  

Microsoft Academic Search

Measurements of plutonium in the terrestrial environment of the Marshall Islands are one indicator of the degree of environmental contamination from nuclear weapons testing. Moreover, the spatial pattern of environmental plutonium concentrations is indicative of the pattern of total radionuclide deposition from all of the nuclear tests. Measurements of plutonium (239+240Pu) to discern the spatial pattern of deposition and the

Steven L Simon; James C Graham; Andrew W Borchert

1999-01-01

367

Plutonium management with thorium-based fuels and inert matrix fuels in thermal reactor systems  

Microsoft Academic Search

The plutonium that is produced by light water reactors worldwide is currently re-used to a limited extent. In the last century, the expected introduction of fast reactors and the associated need for large amounts of plutonium did not take place. The result is that worldwide a stockpile of excess plutonium has formed, which is the dominant contributor to the radiotoxicity

R. P. C. Schram; F. C. Klaassen

2007-01-01

368

THE SEPARATION AND DETERMINATION OF ALUMINUM IN PLUTONIUM-ALUMINUM ALLOYS  

Microsoft Academic Search

ABS>An anion-exchange method was given for the separation of aluminum ; from plutonium in a 1% aluminum-plutonium alloy. After separation, the aluminum ; is determined using oxine, either volumetrically or gravimetrically, or by a ; complexometric titration using EDTA. The volumetric methods are faster. On ; synthetic alloy samples containing 5.00 mg of aluminum and 500 mg of plutonium, ;

F. J. Miner; R. P. Degrazio; C. R. Jr. Forrey; T. C. Jones

1960-01-01

369

A semi-automated approach for processing and extracting low-level plutonium from soil  

Microsoft Academic Search

A semi-automated approach for processing and extracting plutonium from large soil samples has been developed and implemented in our laboratory. The system approach was designed around basic plutonium techniques already published in the literature. The technique was carried out using modular work stations for the major analytical steps, namely; soil leaching, plutonium extraction and phase evaporation. This allowed the laboratory

S. A. Ibrahim; S. B. Webb; F. W. Whicker

1994-01-01

370

OFFGAS GENERATION FROM THE DISPOSITION OF SCRAP PLUTONIUM BY VITRIFICATION SIMULANT TESTS  

Microsoft Academic Search

The Department of Energy Office of Environmental Management is supporting R&D for the conceptual design of the Plutonium Disposition Project at the Savannah River Site in Aiken, SC to reduce the attractiveness of plutonium scrap by fabricating a durable plutonium oxide glass form and immobilizing this form within the high-level waste glass prepared in the Defense Waste Processing Facility. A

J Zamecnik; P Patricia Toole; D David Best; T Timothy Jones; W Whitney Thomas; V Vickie Williams

2008-01-01

371

Chloride removal from plutonium-aluminum alloy dissolver solution prior to purex solvent extraction  

Microsoft Academic Search

The Savannah River Plant (SRP), operated by E. I. du Pont de Nemours Co. for the United States Department of Energy, has successfully recovered plutonium from plutonium-aluminum alloy processed through the F-Canyon Separations facility. The alloy, produced at the Rocky Flats Plant, results from recovery of plutonium residues from spent chloride salts from pyrochemical processing. The alloy, termed scrub alloy''

1990-01-01

372

DEVELOPMENT OF PLUTONIUM RECOVERY PROCESS BY MOLTEN SALT ELECTROREFINING WITH LIQUID CADMIUM CATHODE  

Microsoft Academic Search

The effects of electrochemical conditions on the behaviour of plutonium and adequate conditions for recovery at liquid cadmium cathode (LCC) used in pyrometallugical reprocessing were studied with small, not stirred electrodes. Cathodic current density adequate for plutonium collection at LCC was considered to be controlled by diffusion plutonium ion in molten salt and proportional to its concentration. It was shown

Masatoshi Iizuka; Koich Uozumi; Tadashi Inoue; Takashi Iwai; Osamu Shirai; Yasuo Arai

373

Plutonium contamination in the environment. May 1978-April 1987 (A Bibliography from the Life Sciences Collection data base). Report for May 1978-April 1987  

SciTech Connect

This bibliography contains citations concerning the ecological impact of plutonium contamination in the environment. Topics include plutonium contamination in freshwater and marine sediments, plutonium bioaccumulation, plutonium transport in the food chain, plutonium accumulation in the soil, methods of analysis, plutonium removal from contaminated soils, plutonium contamination from nuclear fallout and nuclear facilities, and the presence of plutonium in seaspray and in the atmosphere. Plutonium biokinetics in humans, and fetal effects from plutonium contamination are also described. (Contains 93 citations fully indexed and including a title list.)

Not Available

1990-05-01

374

MICROBIAL TRANSFORMATIONS OF PLUTONIUM AND IMPLICATIONS FOR ITS MOBILITY.  

SciTech Connect

The current state of knowledge of the effect of plutonium on microorganisms and microbial activity is reviewed, and also the microbial processes affecting its mobilization and immobilization. The dissolution of plutonium is predominantly due to their production of extracellular metabolic products, organic acids, such as citric acid, and sequestering agents, such as siderophores. Plutonium may be immobilized by the indirect actions of microorganisms resulting in changes in Eh and its reduction from a higher to lower oxidation state, with the precipitation of Pu, its bioaccumulation by biomass, and bioprecipitation reactions. In addition, the abundance of microorganisms in Pu-contaminated soils, wastes, natural analog sites, and backfill materials that will be used for isolating the waste and role of microbes as biocolloids in the transport of Pu is discussed.

FRANCIS, A.J.

2000-09-30

375

Oxidation kinetics of plutonium in air: Consequences for environmental dispersal  

SciTech Connect

Kinetic studies show that plutonium corrosion in air is catalyzed by plutonium hydride on the metal surface and suggest that the process has caused storage containers to fail. The catalyzed reaction initiates at 25{degrees}C, indiscriminately consumes both O{sub 2} and N{sub 2}, and transforms metal into a dispersible product at a 10{sup 7}-10{sup 10} faster rate (0.6 {+-} 0.1 g Pu/cm{sup 2} min) than normal air oxidation. The catalyzed Pu+O{sub 2} reaction advances into the metal at a linear rate of 2.9 m/h. Rate equations and particle size data, which are presented for catalyzed and atmospheric corrosion at temperatures up to 3500{degrees}C, provide a technical basis for more accurately assessing the dispersal hazard posed by plutonium metal.

Haschke, J.M.; Allen, T.H.; Martz, J.C.

1997-09-01

376

Characterization and storage of the Rocky Flats plutonium oxide legacy  

SciTech Connect

Prior to 1989, plutonium oxide storage at the U.S. Department of Energy (DOE) Rocky Flats Environmental Technology Site (RFETS) could generally be considered as short term. Packaging configurations for short-term storage consisted of slip-lid cans and sealed produce cans. Prior to packaging, most of the oxide had been stabilized by heating to {approximately}500{degrees}C. When storage times were relatively short, few problems were attributed to either packaging or storage. However, with projected storage times extended up to 50 yr, most of the old packaging of RFETS plutonium oxide will be in two welded steel containers in compliance with the DOE Standard 3013-96, which defines processing and packaging criteria for safe, long-term storage of plutonium oxide.

Stakebake, J.L. [Dept. of Energy, Golden, CO (United States)

1997-12-01

377

Recovery of plutonium from electrorefining anode heels at Savannah River  

SciTech Connect

In a joint effort, the Savannah River Laboratory (SRL), Savannah River Plant (SRP), and the Rocky Flats Plant (RFP) have developed two processes to recover plutonium from electrorefining anode heel residues. Aqueous dissolution of anode heel metal was demonstrated at SRL on a laboratory scale and on a larger pilot scale using either sulfamic acid or nitric acid-hydrazine-fluoride solutions. This direct anode heel metal dissolution requires the use of a geometrically favorable dissolver. The second process developed involves first diluting the plutonium in the anode heel residues by alloying with aluminum. The alloyed anode heel plutonium can then be dissolved using a nitric acid-fluoride-mercury(II) solution in large non-geometrically favorable equipment where nuclear safety is ensured by concentration control.

Gray, J H; Gray, L W; Karraker, D G

1987-03-01

378

Thermal Cycling on Fatigue Failure of the Plutonium Vitrification Melter  

SciTech Connect

One method for disposition of excess plutonium is vitrification into cylindrical wasteforms. Due to the hazards of working with plutonium, the vitrification process must be carried out remotely in a shielded environment. Thus, the equipment must be easily maintained. With their simple design, induction melters satisfy this criterion, making them ideal candidates for plutonium vitrification. However, due to repeated heating and cooling cycles and differences in coefficients of thermal expansion of contacting materials fatigue failure of the induction melter is of concern. Due to the cost of the melter, the number of cycles to failure is critical. This paper presents a method for determining the cycles to failure for an induction melter by using the results from thermal and structural analyses as input to a fatigue failure model.

Jordan, Jeffrey; Gorczyca, Jennifer

2009-02-11

379

Subcritical Noise Measurements with a Nickel-Reflected Plutonium Sphere  

SciTech Connect

Subcritical measurements were conducted with an a-phase plutonium sphere reflected by nickel hemishells using the 252Cf Source-Driven Noise Analysis (CSDNA) method to provide criticality safety benchmark data. Measured configurations included a bare plutonium sphere as well as the plutonium sphere reflected by the following nickel thicknesses: 1.27, 2.54, 3.81, 5.08, and 7.62 cm. A certain ratio of spectral quantities was measured for each configuration which varies linearly with the keff of the system. In addition, two types of Monte Carlo calculations were employed: a modified version of MCNP to calculate the ratio of spectral quantities and a KCODE calculation. From the measured and computed quantities the multiplication of each configuration can be approximated. A comprehensive uncertainty analysis was then performed that includes uncertainties in the geometry and materials present in the system in addition to the uncertainties in the method and nuclear data.

Jesson D. Hutchinson; John D. Bess

2009-11-01

380

Extraction of Uranium, Neptunium and Plutonium from Caustic Media  

SciTech Connect

5 Fundamental research on uranium, neptunium and plutonium separation from alkaline media using solvent extraction is being conducted. Specific extractants for these actinides from alkaline media have been synthesized to investigate the feasibility of selective removal of these elements. Two families of extractants have been studied: terephthalamide and tetra(hydroxybenzyl)ethylene diamine derivatives. Fundamental studies were conducted to characterize their extraction behavior from a wide variety of aqueous conditions. The terephthalamide derivatives exhibit a significant extraction strength along with a discriminatory behavior among the actinides, plutonium being extracted the most strongly. Quantitative extraction of plutonium and moderate extraction of neptunium and uranium was achieved from a simple caustic solution. Interestingly, strontium is also quantitatively extracted by these derivatives. However, their stability to highly caustic solutions still needs to be imp roved. Tetra(hydroxybenzyl)ethylene diamine derivatives exhibit a very good stability to caustic conditions and are currently being studied.

Delmau, Laetitia H.; Bonnesen, Peter V.; Engle, Nancy L.; Raymond, Kenneth N.; Xu, Jade

2004-03-28

381

Electronic structure and magnetic susceptibility of monoclinic ?-plutonium  

NASA Astrophysics Data System (ADS)

The electronic structure of the ?-phase of plutonium has been calculated by the band methods with allowance for the spin-orbit interaction and Coulomb correlations in the complete matrix form (the LDA + U + SO method). The strong spin-orbit interaction of the 5 f electrons is manifested in the splitting of the calculated density of the 5 f states, which makes a small contribution at the Fermi level on the order of the contribution from the 6 d states. Using the results of the ab initio calculations, the spin and orbit contributions to the magnetic susceptibility of ?-plutonium have been determined. Along with the impurity contribution, they describe well the experimental data on the susceptibility of this plutonium phase to a temperature of 300 K.

Povzner, A. A.; Filanovich, A. N.; Shorikov, A. O.; Lukoyanov, A. V.; Volkov, A. G.

2014-08-01

382

Isotopic Measurements: Interpretation and Implications of Plutonium Data  

SciTech Connect

One of the fundamental activities within the field of nuclear forensics is the laboratory analysis of nuclear material; one aspect is providing the isotopic composition of the material under investigation. For both plutonium and uranium, this includes a unique suite of isotopes that, individually and collectively (i.e. an isotopic vector), will help characterize these materials, and potentially provide insight into their mode of production, intended utilization, and processing history. A full understanding of how this information is used provides the basis for defining the need for these measurements and helps determine the precision and accuracy requirements for those measurements. This paper provides an overview of this process as it applies to plutonium, discussing how reactor design and operating parameters can impact the resultant plutonium vector, thereby giving us the ability to infer those reactor traits based on isotopic measurements.

Luksic, Andrzej T.; Collins, Brian A.; Friese, Judah I.; Schwantes, Jon M.; Starner, Jason R.; Wacker, John F.

2010-08-11

383

Plutonium (III) and uranium (III) nitrile complexes  

SciTech Connect

Iodine oxidation of uranium and plutonium metals in tetrahydrofuran and pyridine form AnI{sub 3}(THF){sub 4} and AnI{sub 3}(py){sub 4} (An = Pu, U). These compounds represent convenient entries Into solution An(III) chemistry in organic solvents. Extensions of the actinide metal oxidation methodology in nitrile solvents by I{sub 2}, AgPF{sub 6}, and TIPF{sub 6} are presented here. Treatment of Pu{sup 0} in acetonitrile with iodine yields a putative PuI{sub 3}(NCMe){sub x} intermediate which can be trapped with the tripodal nitrogen donor ligand tpza (tpza = (tris[(2-pyrazinyl)methyl]amine)) and forms the eight-coordinate complex (tpza)PuI{sub 3}(NCMe). Treatment of excess U{sup 0} metal by iodine in acetonitrile afforded a brown crystalline mixed valence complex, [U(NCMe){sub 9}][UI{sub 6}][I], instead of UI{sub 3}(NCMe){sub 4}. The analogous reaction in bezonitrile forms red crystalline UI{sub 4}(NCPh){sub 4}. In contrast, treatment of UI{sub 3}(THF){sub 4} with excess acetonitrile cleanly generates [U(NCMe){sub 9}][I]{sub 3}. Oxidation of Pu{sup 0} by either TI(I) or Ag(I) hexafluorophosphate salts generates a nine-coordinate homoleptic acetonitrile adduct [Pu(NCMe){sub 9}][PF{sub 6}]{sub 3}. Attempts to oxidize U{sub 0} with these salts were unsuccessful.

Enriquez, A. E. (Alejandro E.); Matonic, J. H. (John H.); Scott, B. L. (Brian L.); Neu, M. P. (Mary P.)

2002-01-01

384

Evaluating global atmospheric transport of plutonium with dust aerosols  

NASA Astrophysics Data System (ADS)

The resuspension of soils contaminated with radionuclides from nuclear weapons tests is a mechanism by which plutonium can be re-distributed throughout the environment. To better understand the global atmospheric transport of plutonium, we measured the activity of Pu in aerosol samples from four widely separated sites that receive dust from distant sources in both Asia and Africa. High-volume aerosol samples were collected from Barbados (2005 - 2006); Gosan, South Korea (2005 - 2006); Izaña, Canary Islands (1989 - 1996); and Mauna Loa Observatory, Hawaii (2005 - 2006) to evaluate the relationship between Pu activity and mineral dust concentrations (using crustal elements such as aluminum as a dust proxy). The activity of 239,240Pu (239Pu + 240Pu) in the aerosol samples was determined by alpha spectrometry following a series of chemical separations. Concentrations of other elements were determined by a variety of techniques. Pu activity was below the detection limit in many samples. In those samples where it was detected, the Gosan site had the highest dust concentrations and highest total plutonium activity, while Mauna Loa Observatory had the lowest dust concentrations and lowest 239,240Pu activity. The Izaña samples had the second highest concentrations of dust and plutonium activity, while Barbados had the third highest levels of both crustal aerosols and plutonium activity. The dust concentrations are consistent with previous observations at these remote sites, and we propose that the plutonium (primarily from past atmospheric nuclear weapons testing, much of which took place in arid lands) was deposited on erodible soil surfaces and subsequently transported as part of the overall mineral dust load. The results of this study have implications for the global transport and fate of Pu through its association with dust, the biogeochemical and environmental impacts of other substances associated with dust, and the workings of the dust cycle itself.

Velarde, R.; Arimoto, R.; Gill, T. E.; Kang, C.; Goodell, P.

2009-12-01

385

Integrated development and testing plan for the plutonium immobilization project  

SciTech Connect

This integrated plan for the DOE Office of Fissile Materials Disposition (MD) describes the technology development and major project activities necessary to support the deployment of the immobilization approach for disposition of surplus weapons-usable plutonium. The plan describes details of the development and testing (D&T) tasks needed to provide technical data for design and operation of a plutonium immobilization plant based on the ceramic can-in-canister technology (''Immobilization Fissile Material Disposition Program Final Immobilization Form Assessment and Recommendation'', UCRL-ID-128705, October 3, 1997). The plan also presents tasks for characterization and performance testing of the immobilization form to support a repository licensing application and to develop the basis for repository acceptance of the plutonium form. Essential elements of the plant project (design, construction, facility activation, etc.) are described, but not developed in detail, to indicate how the D&T results tie into the overall plant project. Given the importance of repository acceptance, specific activities to be conducted by the Office of Civilian Radioactive Waste Management (RW) to incorporate the plutonium form in the repository licensing application are provided in this document, together with a summary of how immobilization D&T activities provide input to the license activity. The ultimate goal of the Immobilization Project is to develop, construct, and operate facilities that will immobilize from about 18 to 50 tonnes (MT) of U.S. surplus weapons usable plutonium materials in a manner that meets the ''spent fuel'' standard (Fissile Materials Storage and Disposition Programmatic Environmental Impact Statement Record of Decision, ''Storage and Disposition Final PEIS'', issued January 14, 1997, 62 Federal Register 3014) and is acceptable for disposal in a geologic repository. In the can-in-canister technology, this is accomplished by encapsulating the plutonium-containing ceramic forms within large canisters of high level waste (HLW) glass. Deployment of the immobilization capability should occur by 2006 and be completed within 10 years.

Kan, T.

1998-07-01

386

Effect of Carbon Dioxide Variations on Climate  

Microsoft Academic Search

Variations in the amount of atmospheric carbon dioxide cause temperature changes sufficiently large to influence the climate. If the atmospheric carbon dioxide doubles, the surface temperature rises 3.6°C if it is cut in half, the surface temperature falls 3.8°C. Some of the factors that can be explained by the carbon dioxide theory are: during a single glacial epoch, the climate

Gilbert N. Plass

1956-01-01

387

Proceedings of the Plutonium Futures ? The Science 2006 Conference  

SciTech Connect

Plutonium Futures--The Science 2006 provided opportunities to examine present knowledge of the chemical and physical properties of plutonium and other actinides in complex media and materials; to discuss the current and emerging science (chemistry, physics, materials science, nuclear science, and environmental effects) of plutonium and actinides relevant to enhancing global nuclear security; and to exchange ideas. This international conference also provided a forum for illustrating and enhancing capabilities and interests, and assessing issues in these areas. U.S. and international scientists, engineers, faculty, and students from universities, national laboratories, and DOE's nuclear complex were encouraged to participate and make technical contributions. The Conference ran from Sunday, July 9th through Thursday, July 13th. A popular aspect of the conference was the opening tutorial session on Sunday afternoon intended for students and scientists new to the area of plutonium research. The tutorial was well attended by novices and veterans alike, and featured such diverse topics as; plutonium metallurgy, plutonium in the environment, and international arms control and nonproliferation. Two plenary lectures began each morning and each afternoon session and highlighted the breakout sessions on coordination/organometallic chemistry, solid-state physics, environmental chemistry, materials science, separations and reprocessing, advanced fuels and waste forms, phase transformations, solution and gas-phase chemistry, compounds and complexes, electronic structure and physical properties, and more. Chemistry Highlights--Among the many chemistry highlights presented in this proceedings are the overview of concepts and philosophies on inert nuclear fuel matrices and concerns about the ever-increasing amounts of minor actinides and plutonium generated in the fuel cycle. The various ideas involve multiple reduction schemes for these materials, suggesting fuels for 'burning' or 'cradle-to-grave' accountability for various reactor types. Related work is presented on identification of the unique reaction mechanisms and identification of the intermediate products, including Pu(III), at the end of the PUREX process. In the important area of nuclear forensics, actual scenarios of nuclear materials confiscation and the successes of applying forensics protocols to determine attribution and possible intention are provided. In the area of reactor incidents, there is no other place on Earth like the Chernobyl Site Object Shelter and radioactive aerosol particle characterization studies reflect an important effort described herein. An additional report from another unique environmental site presents results on radionuclide monitoring, fate, and transport in the ecosystem of the Yenisei River in the Krasoyarsk region. In the area of nuclear waste disposal, a study of the ion irradiation damage to pyrochlore compounds with varying amounts of host elements and actinide dopants is presented. Papers on both the aqueous and nonaqueous chemistry of plutonium and other actinides are presented including anhydrous coordination chemistry and redox behavior in the presence of humic materials and the their sorption on common minerals in the environment. Also published herein are reports on the field of anhydrous coordination chemistry of the transuranic elements where there is scarce information. Solid-State and Materials Highlights--Plutonium solid-state and materials research is represented in these proceedings by a wealth of leading edge discovery class research. The breadth of this research is reflected in the topics covered: solid-state; materials science; superconductivity; phase changes, phonons, and entropy; electronic structure and physical properties; surface science and corrosion; and radiation effects, defects, impurities, and property changes. Indeed the scientific challenge and excitement of plutonium can best be highlighted by quoting the tutorial prospectus of Drs. Sarrao and Schwartz. 'Plutonium has long been recognized as a complex and scie

Fluss, M; Hobart, D; Allan, P; Jarvinen, G

2007-07-12

388

Plutonium immobilization plant using glass in new facilities at the Savannah River Site  

SciTech Connect

The Plutonium Immobilization Plant (PIP) accepts plutonium (Pu) from pit conversion and from non-pit sources and, through a glass immobilization process, converts the plutonium into an immobilized form that can be disposed of in a high level waste (HLW) repository. This immobilization process is shown conceptually in Figure 1-1. The objective is to make an immobilized form, suitable for geologic disposal, in which the plutonium is as inherently unattractive and inaccessible as the plutonium in spent fuel from commercial reactors.

DiSabatino, A.

1998-06-01

389

Minutes of the 28th Annual Plutonium Sample Exchange Meeting. Part II: metal sample exchange  

SciTech Connect

Contents of this publication include the following list of participating laboratories; agenda; attendees; minutes of October 25 and 26 meeting; and handout materials supplied by speakers. The handout materials cover the following: statistics and reporting; plutonium - chemical assay 100% minus impurities; americium neptunium, uranium, carbon and iron data; emission spectroscopy data; plutonium metal sample exchange; the calorimetry sample exchange; chlorine determination in plutonium metal using phyrohydrolysis; spectrophotometric determination of 238-plutonium in oxide; plutonium measurement capabilities at the Savannah River Plant; and robotics in radiochemical laboratory.

Not Available

1984-01-01

390

A study on determination of potentially hazardous plutonium isotopes in environmental samples.  

PubMed

Due to the lack of stable plutonium isotopes, and the high mobility as well as long half-life, plutonium is considered one of the most important radioelement in safety assessment of environmental radioactivity and nuclear waste management. A number of analytical methods have been developed over the past decades for determination of plutonium in environmental samples. The article discusses different analytical techniques and presents the results of plutonium isotopes determination by alpha spectrometry and accelerator mass spectrometry in environmental samples. The concentrations of plutonium isotopes in analyzed samples indicates its measurement is of great importance for environmental and safety assessment, especially in contaminated areas. PMID:23672404

Strumi?ska-Parulska, Dagmara I

2013-01-01

391

Surface charging of silicon dioxide and aluminum dioxide structures  

NASA Astrophysics Data System (ADS)

The well-known technique of insulator surface charging is performed here with a tip of a cantilever. The feasibility to prepare a surface charge memory device is discussed. Since the charging of high resistive insulator surfaces can be performed approximately without power consumption and the surface charging is a promising method to build memory devices in integrated electronic circuits. To this aim the surface of silicon dioxide (SiO2) is charged with the tip of an atomic force microscope (AFM) for different charging voltage, different charging time and different thickness of the sample in contact mode. Afterwards, the charged surface is inspected with the same tip operated in the Kelvin mode. With the Kelvin option of the AFM the surface potential and topography of the samples can be measured simultaneously. Furthermore, a time dependent spread and an exponential-like decay of the surface potential with a time constant of about 15 h are observed . Due to this long-term stability and the possibility to reverse the sign of the deposited charge by recharging in opposite direction it is thinkable to use the system as a surface charge memory device. Additionally, surface potential measurements are performed on aluminum dioxide (Al2O3) samples.

Rathi, Abhishek; Martin, Bjoern

2012-10-01

392

Carbon dioxide and intergenerational choice  

SciTech Connect

Depending on ethical beliefs, different decisions emerge for resolving the carbon dioxide (CO/sup 2/) issue. It is doubtful that an international consensus can be reached on a correct ethical criterion. Perhaps the best strategy would be to delay acceptance of either a particular set of beliefs or the existing scientific evidence and wait for more-accurate and conclusive research to emerge. If the scientific evidence is accepted as valid, and all future generations that will exist are evaluated equally, then the optimal current regulatory strategy is to restrict, as much as possible, current emissions of CO/sup 2/. 17 references, 2 figure, 1 table.

D'Arge, R.C.; Schulze, W.D.; Brookshire, D.S.

1982-05-01

393

Plutonium solution storage in plastic bottles: Operational experience and safety issues  

SciTech Connect

Computer spread sheet models were developed to gain a better understanding of the factors that lead to pressurization and failure of plastic bottles containing plutonium solutions. These models were developed using data obtained from the literature on gas generation rates for plutonium solutions. Leak rates from sealed plastic bottles were obtained from bottle leak tests conducted at Rocky Flats. Results from these bottle leak tests showed that narrow mouth four liter bottles will seal much better than wide mouth four liter bottles. The gas generation rate and leak rate data were used to develop models for predicting the rate of pressurization and maximum pressures expected in sealed bottles of plutonium solution containing various plutonium and acid concentrations. The computer models were used to develop proposed time limits for storing or transporting plutonium solutions in sealed plastic bottles. For plutonium solutions containing < 1.5 g/l, maximum safe storage times from 4 weeks to 12 months are proposed. The maximum safe storage times vary depending upon the plutonium concentration in the solution. Low concentration plutonium solutions can be stored safely for longer periods of time than high concentration plutonium solutions. For solutions containing > 1.5 g/l plutonium, storage in sealed bottles should not be allowed. However, transportation of higher concentration plutonium solution in sealed bottles is required, and safe transportation times of 1 shift to 6 days are proposed.

Conner, W.V.

1995-03-15

394

Thermodynamic Promotion of Carbon Dioxide Clathrate Hydrate Formation by  

E-print Network

Thermodynamic Promotion of Carbon Dioxide Clathrate Hydrate Formation by Tetrahydrofuran, Cyclopentane)-vapour (V) equilibrium pressures for the ternary system composed of water, tetrahydrofuran (THF), and carbon and carbon dioxide. Keywords: Gas Hydrates, carbon dioxide capture, tetrahydrofuran, cyclopentane

Paris-Sud XI, Université de

395

46 CFR 169.565 - Fixed carbon dioxide system.  

Code of Federal Regulations, 2013 CFR

... 2013-10-01 false Fixed carbon dioxide system. 169.565 Section 169.565...Firefighting Equipment § 169.565 Fixed carbon dioxide system. (a) The number of pounds of carbon dioxide required for each space protected...

2013-10-01

396

46 CFR 95.15-20 - Carbon dioxide storage.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Carbon dioxide storage. 95.15-20 Section 95...VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 95.15-20 Carbon dioxide storage. (a) Except as...

2013-10-01

397

21 CFR 868.2385 - Nitrogen dioxide analyzer.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Nitrogen dioxide analyzer. 868.2385 Section 868...Monitoring Devices § 868.2385 Nitrogen dioxide analyzer. (a) Identification. The nitrogen dioxide analyzer is a device intended to...

2011-04-01

398

21 CFR 868.5310 - Carbon dioxide absorber.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Carbon dioxide absorber. 868.5310 Section 868...Therapeutic Devices § 868.5310 Carbon dioxide absorber. (a) Identification. A carbon dioxide absorber is a device that is...

2012-04-01

399

46 CFR 76.15-20 - Carbon dioxide storage.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Carbon dioxide storage. 76.15-20 Section 76...VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 76.15-20 Carbon dioxide storage. (a) Except as...

2011-10-01

400

21 CFR 868.2385 - Nitrogen dioxide analyzer.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Nitrogen dioxide analyzer. 868.2385 Section 868...Monitoring Devices § 868.2385 Nitrogen dioxide analyzer. (a) Identification. The nitrogen dioxide analyzer is a device intended to...

2012-04-01

401

46 CFR 97.37-9 - Carbon dioxide alarm.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Carbon dioxide alarm. 97.37-9 Section 97.37-9...Emergency Equipment, Etc. § 97.37-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified:...

2010-10-01

402

21 CFR 868.1400 - Carbon dioxide gas analyzer.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Carbon dioxide gas analyzer. 868.1400 Section 868...Diagnostic Devices § 868.1400 Carbon dioxide gas analyzer. (a) Identification. A carbon dioxide gas analyzer is a device intended to...

2012-04-01

403

40 CFR 52.795 - Control strategy: Sulfur dioxide.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Control strategy: Sulfur dioxide. 52.795 Section 52.795 Protection...52.795 Control strategy: Sulfur dioxide. (a) Revised APC-13 (December...Pollution Control regulations (sulfur dioxide emission limitation) is...

2011-07-01

404

40 CFR 52.795 - Control strategy: Sulfur dioxide.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Control strategy: Sulfur dioxide. 52.795 Section 52.795 Protection...52.795 Control strategy: Sulfur dioxide. (a) Revised APC-13 (December...Pollution Control regulations (sulfur dioxide emission limitation) is...

2013-07-01

405

46 CFR 151.50-84 - Sulfur dioxide.  

...2014-10-01 2014-10-01 false Sulfur dioxide. 151.50-84 Section 151.50-84 Shipping... Special Requirements § 151.50-84 Sulfur dioxide. (a) Sulfur dioxide that is transported under the provisions of...

2014-10-01

406

21 CFR 868.2385 - Nitrogen dioxide analyzer.  

...2014-04-01 2014-04-01 false Nitrogen dioxide analyzer. 868.2385 Section 868...Monitoring Devices § 868.2385 Nitrogen dioxide analyzer. (a) Identification. The nitrogen dioxide analyzer is a device intended to...

2014-04-01

407

21 CFR 868.2385 - Nitrogen dioxide analyzer.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Nitrogen dioxide analyzer. 868.2385 Section 868...Monitoring Devices § 868.2385 Nitrogen dioxide analyzer. (a) Identification. The nitrogen dioxide analyzer is a device intended to...

2010-04-01

408

46 CFR 95.15-20 - Carbon dioxide storage.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Carbon dioxide storage. 95.15-20 Section 95...VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 95.15-20 Carbon dioxide storage. (a) Except as...

2011-10-01

409

21 CFR 868.5300 - Carbon dioxide absorbent.  

...2014-04-01 2014-04-01 false Carbon dioxide absorbent. 868.5300 Section 868...Therapeutic Devices § 868.5300 Carbon dioxide absorbent. (a) Identification. A carbon dioxide absorbent is a device intended for...

2014-04-01

410

40 CFR 86.524-78 - Carbon dioxide analyzer calibration.  

...2014-07-01 2014-07-01 false Carbon dioxide analyzer calibration. 86.524-78...Procedures § 86.524-78 Carbon dioxide analyzer calibration. (a) Prior...and monthly thereafter the NDIR carbon dioxide analyzer shall be calibrated:...

2014-07-01

411

46 CFR 151.50-84 - Sulfur dioxide.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Sulfur dioxide. 151.50-84 Section 151.50-84 Shipping... Special Requirements § 151.50-84 Sulfur dioxide. (a) Sulfur dioxide that is transported under the provisions of...

2010-10-01

412

40 CFR 52.1676 - Control strategy: Nitrogen dioxide.  

... false Control strategy: Nitrogen dioxide. 52.1676 Section 52.1676 Protection...52.1676 Control strategy: Nitrogen dioxide. (a) The requirements of...hydrocarbons, ozone, and nitrogen dioxide. [37 FR 19815, Sept. 22,...

2014-07-01

413

21 CFR 868.2385 - Nitrogen dioxide analyzer.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Nitrogen dioxide analyzer. 868.2385 Section 868...Monitoring Devices § 868.2385 Nitrogen dioxide analyzer. (a) Identification. The nitrogen dioxide analyzer is a device intended to...

2013-04-01

414

21 CFR 868.5310 - Carbon dioxide absorber.  

...2014-04-01 2014-04-01 false Carbon dioxide absorber. 868.5310 Section 868...Therapeutic Devices § 868.5310 Carbon dioxide absorber. (a) Identification. A carbon dioxide absorber is a device that is...

2014-04-01

415

46 CFR 151.50-84 - Sulfur dioxide.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Sulfur dioxide. 151.50-84 Section 151.50-84 Shipping... Special Requirements § 151.50-84 Sulfur dioxide. (a) Sulfur dioxide that is transported under the provisions of...

2011-10-01

416

21 CFR 868.1400 - Carbon dioxide gas analyzer.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Carbon dioxide gas analyzer. 868.1400 Section 868...Diagnostic Devices § 868.1400 Carbon dioxide gas analyzer. (a) Identification. A carbon dioxide gas analyzer is a device intended to...

2013-04-01

417

40 CFR 52.795 - Control strategy: Sulfur dioxide.  

...2014-07-01 false Control strategy: Sulfur dioxide. 52.795 Section 52.795 Protection...52.795 Control strategy: Sulfur dioxide. (a) Revised APC-13 (December...Pollution Control regulations (sulfur dioxide emission limitation) is...

2014-07-01

418

46 CFR 108.626 - Carbon dioxide warning signs.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Carbon dioxide warning signs. 108.626 Section...and Instructions § 108.626 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by...

2013-10-01

419

46 CFR 108.431 - Carbon dioxide systems: General.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Carbon dioxide systems: General. 108.431 Section...Fire Extinguishing Systems Fixed Carbon Dioxide Fire Extinguishing Systems § 108.431 Carbon dioxide systems: General. (a)...

2011-10-01

420

46 CFR 108.431 - Carbon dioxide systems: General.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Carbon dioxide systems: General. 108.431 Section...Fire Extinguishing Systems Fixed Carbon Dioxide Fire Extinguishing Systems § 108.431 Carbon dioxide systems: General. (a)...

2012-10-01

421

46 CFR 97.37-9 - Carbon dioxide alarm.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Carbon dioxide alarm. 97.37-9 Section 97.37-9...Emergency Equipment, Etc. § 97.37-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified:...

2011-10-01

422

21 CFR 868.5300 - Carbon dioxide absorbent.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Carbon dioxide absorbent. 868.5300 Section 868...Therapeutic Devices § 868.5300 Carbon dioxide absorbent. (a) Identification. A carbon dioxide absorbent is a device intended for...

2013-04-01

423

46 CFR 76.15-20 - Carbon dioxide storage.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Carbon dioxide storage. 76.15-20 Section 76...VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 76.15-20 Carbon dioxide storage. (a) Except as...

2013-10-01

424

46 CFR 108.431 - Carbon dioxide systems: General.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Carbon dioxide systems: General. 108.431 Section...Fire Extinguishing Systems Fixed Carbon Dioxide Fire Extinguishing Systems § 108.431 Carbon dioxide systems: General. (a)...

2013-10-01

425

46 CFR 108.431 - Carbon dioxide systems: General.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Carbon dioxide systems: General. 108.431 Section...Fire Extinguishing Systems Fixed Carbon Dioxide Fire Extinguishing Systems § 108.431 Carbon dioxide systems: General. (a)...

2010-10-01

426

21 CFR 868.5310 - Carbon dioxide absorber.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Carbon dioxide absorber. 868.5310 Section 868...Therapeutic Devices § 868.5310 Carbon dioxide absorber. (a) Identification. A carbon dioxide absorber is a device that is...

2011-04-01

427

46 CFR 108.626 - Carbon dioxide warning signs.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Carbon dioxide warning signs. 108.626 Section...and Instructions § 108.626 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by...

2012-10-01

428

46 CFR 76.15-20 - Carbon dioxide storage.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Carbon dioxide storage. 76.15-20 Section 76...VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 76.15-20 Carbon dioxide storage. (a) Except as...

2012-10-01

429

21 CFR 868.5300 - Carbon dioxide absorbent.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Carbon dioxide absorbent. 868.5300 Section 868...Therapeutic Devices § 868.5300 Carbon dioxide absorbent. (a) Identification. A carbon dioxide absorbent is a device intended for...

2012-04-01

430

46 CFR 95.15-20 - Carbon dioxide storage.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Carbon dioxide storage. 95.15-20 Section 95...VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 95.15-20 Carbon dioxide storage. (a) Except as...

2012-10-01

431

40 CFR 52.795 - Control strategy: Sulfur dioxide.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Control strategy: Sulfur dioxide. 52.795 Section 52.795 Protection...52.795 Control strategy: Sulfur dioxide. (a) Revised APC-13 (December...Pollution Control regulations (sulfur dioxide emission limitation) is...

2012-07-01

432

46 CFR 151.50-84 - Sulfur dioxide.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Sulfur dioxide. 151.50-84 Section 151.50-84 Shipping... Special Requirements § 151.50-84 Sulfur dioxide. (a) Sulfur dioxide that is transported under the provisions of...

2012-10-01

433

21 CFR 868.5300 - Carbon dioxide absorbent.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Carbon dioxide absorbent. 868.5300 Section 868...Therapeutic Devices § 868.5300 Carbon dioxide absorbent. (a) Identification. A carbon dioxide absorbent is a device intended for...

2011-04-01

434

21 CFR 868.5310 - Carbon dioxide absorber.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Carbon dioxide absorber. 868.5310 Section 868...Therapeutic Devices § 868.5310 Carbon dioxide absorber. (a) Identification. A carbon dioxide absorber is a device that is...

2013-04-01

435

46 CFR 151.50-84 - Sulfur dioxide.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Sulfur dioxide. 151.50-84 Section 151.50-84 Shipping... Special Requirements § 151.50-84 Sulfur dioxide. (a) Sulfur dioxide that is transported under the provisions of...

2013-10-01

436

46 CFR 193.15-20 - Carbon dioxide storage.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Carbon dioxide storage. 193.15-20 Section 193...VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 193.15-20 Carbon dioxide storage. (a) Except as...

2011-10-01

437

46 CFR 169.565 - Fixed carbon dioxide system.  

Code of Federal Regulations, 2012 CFR

... 2012-10-01 false Fixed carbon dioxide system. 169.565 Section 169.565...Firefighting Equipment § 169.565 Fixed carbon dioxide system. (a) The number of pounds of carbon dioxide required for each space protected...

2012-10-01

438

PLUTONIUM UPTAKE BY PLANTS GROWN IN SOLUTION CULTURE  

EPA Science Inventory

Plants grown in aquatic systems were shown to rapidly accumulate large amounts of plutonium, about 40% of which was removed by washing. Detergent removed debris, most of which consisted of particles larger than 0.8 micrometers. After removing a portion of the bound Pu by rinsing ...

439

Plutonium Consumption Program, CANDU Reactor Project final report  

SciTech Connect

DOE is investigating methods for long term dispositioning of weapons grade plutonium. One such method would be to utilize the plutonium in Mixed OXide (MOX) fuel assemblies in existing CANDU reactors. CANDU (Canadian Deuterium Uranium) reactors are designed, licensed, built, and supported by Atomic Energy of Canada Limited (AECL), and currently use natural uranium oxide as fuel. The MOX spent fuel assemblies removed from the reactor would be similar to the spent fuel currently produced using natural uranium fuel, thus rendering the plutonium as unattractive as that in the stockpiles of commercial spent fuel. This report presents the results of a study sponsored by the DOE for dispositioning the plutonium using CANDU technology. Ontario Hydro`s Bruce A was used as reference. The fuel design study defined the optimum parameters to disposition 50 tons of Pu in 25 years (or 100 tons). Two alternate fuel designs were studied. Safeguards, security, environment, safety, health, economics, etc. were considered. Options for complete destruction of the Pu were also studied briefly; CANDU has a superior ability for this. Alternative deployment options were explored and the potential impact on Pu dispositioning in the former Soviet Union was studied. An integrated system can be ready to begin Pu consumption in 4 years, with no changes required to the reactors other than for safe, secure storage of new fuel.

Not Available

1994-07-31

440

Evaluation of source-term data for plutonium aerosolization  

SciTech Connect

Relevant data are reviewed and evaluated in an effort to define the time dependence and maximum value of the source term for plutonium aerosolization during a fuel fire. The rate of plutonium oxidation at high temperatures is a major determinant of the time dependence. Analysis of temperature-time data for oxidation of plutonium shows that the rate is constant (0.2 g PUO{sub 2}/cm{sup 2} of metal surface per min) and independent of temperature above 500{degrees}C. Total mass and particle distributions are derived for oxide products formed by reactions of plutonium metal and hydride. The mass distributions for products of all metal-gas reactions are remarkably similar with approximately 0.07 mass% of the oxide particles having geometric diameters {le} 10 {mu}m. In comparison, 25 mass% of the oxide formed by the PuH{sub 2}+O{sub 2} reaction is in this range. Experimental values of mass fractions released during oxidation are evaluated and factors that alter the release fraction are discussed.

Haschke, J.M.

1992-07-01

441

Plutonium Focus Area research and development plan. Revision 1  

SciTech Connect

The Department of Energy (DOE) committed to a research and development program to support the technology needs for converting and stabilizing its nuclear materials for safe storage. The R and D Plan addresses five of the six material categories from the 94-1 Implementation Plan: plutonium (Pu) solutions, plutonium metals and oxides, plutonium residues, highly enriched uranium, and special isotopes. R and D efforts related to spent nuclear fuel (SNF) stabilization were specifically excluded from this plan. This updated plan has narrowed the focus to more effectively target specific problem areas by incorporating results form trade studies. Specifically, the trade studies involved salt; ash; sand, slag, and crucible (SS and C); combustibles; and scrub alloy. The plan anticipates possible disposition paths for nuclear materials and identifies resulting research requirements. These requirements may change as disposition paths become more certain. Thus, this plan represents a snapshot of the current progress and will continue to be updated on a regular basis. The paper discusses progress in safeguards and security, plutonium stabilization, special isotopes stabilization, highly-enriched uranium stabilization--MSRE remediation project, storage technologies, engineered systems, core technology, and proposed DOE/Russian technology exchange projects.

NONE

1996-11-01

442

MIXED RADIATION DOSIMETRY OF A PLUTONIUM-BERYLLIUM NEUTRON SOURCE  

Microsoft Academic Search

The dose rate delivered to an assumed standard tissue by the fast-; neutron and gamma -radiation from a standard 1 c plutonium-beryllium neutron ; source was determined by measurements with ethylene-filled polyethylene and CO\\/; sub 2-\\/ filled Teflon ionization chambers. The resulting ionization currents as ; measured with a calibrated vibrating-reed electrometer were used to obtain a ; measure of

Donald C. Lawrence

1962-01-01

443

Dissolution of Fissile Materials Containing Plutonium and Beryllium Metals  

Microsoft Academic Search

Scrap materials containing plutonium (Pu) metal were dissolved at the Savannah River Site (SRS) as part of a program to disposition nuclear materials during the deactivation of the FB?Line facility. Some of these items contained both Pu and beryllium (Be) metal as a composite material. The Pu and Be metals were physically separated to minimize the amount of Be associated

Tracy S. Rudisill; Mark L. Crowder

2006-01-01

444

A NEW SOLVENT FOR PLUTONIUM EXTRACTION-TRILAURYLAMINE  

Microsoft Academic Search

The extraction and purification methods for plutonium are essentially ; based at the moment on the use of tributylphosphate (TBP). A tertiary amine, ; trilaurylamine (TLA) was used on a laboratory scale with a view to obtaining ; performances at least comparahle to those of TBP. Its use is recommended in the ; case of solutions having a high BETA

Chesne

1962-01-01

445

Plutonium explosive dispersal modeling using the MACCS2 computer code  

Microsoft Academic Search

The purpose of this paper is to derive the necessary parameters to be used to establish a defensible methodology to perform explosive dispersal modeling of respirable plutonium using Gaussian methods. A particular code, MACCS2, has been chosen for this modeling effort due to its application of sophisticated meteorological statistical sampling in accordance with the philosophy of Nuclear Regulatory Commission (NRC)

C. M. Steele; T. L. Wald; D. I. Chanin

1998-01-01

446

Bacterial Biotransformations for the In situ Stabilization of Plutonium  

SciTech Connect

Plutonium contamination in the environment is generally low-level and may be present and transported in a range of forms (IV, V, VI). Current remediation strategies are costly, financially and in terms of increased exposure risk to people and the environment. In situ bacterial biostabilization is a promising alternative.

Neu, Mary; Boukhalfa, Hakim; Icopini, Gary; Hersman, Larry; Lack, Joe; Priester, John; Olson, Scott; Holden, Patricia

2005-04-20

447

Ultratrace Analysis of Uranium and Plutonium By Mass Spectrometry  

SciTech Connect

At the Pacific Northwest National Laboratory (PNNL), we have developed highly sensitive methods to analyze uranium and plutonium in environmental samples. The development of an ultratrace analysis capability for measuring uranium and plutonium has arisen from a need to detect and characterize environmental samples for signatures associated with nuclear industry processes. Our most sensitive well-developed methodologies employ thermal ionization mass spectrometry (TIMS), however, recent advances in inductively coupled plasma mass spectrometry (ICP-MS) have shown considerable promise for use in detecting uranium and plutonium at ultratrace levels. The work at PNNL has included the development of both chemical separation and purification techniques, as well as the development of mass spectrometric instrumentation and techniques. At the heart of our methodology for TIMS analysis is a procedure that utilizes 100-microliter-volumes of analyte for chemical processing to purify, separate, and load actinide elements into resin beads for subsequent mass spectrometric analysis. The resin bead technique has been combined with a thorough knowledge of the physicochemistry of thermal ion emission to achieve femtogram detection limits for the TIMS analysis of plutonium in environmental samples.

Wacker, John F.; Wogman, Ned A.; Olsen, Khris B.; Petersen, Steven L.; Farmer, O T.; Kelley, James M.; Eiden, Greg C.; Maiti, Tapas C.

2003-01-01

448

Post-accident inhalation exposure and experience with plutonium  

Microsoft Academic Search

This paper addresses the issue of inhalation exposure immediately afterward and for a long time following a nuclear accident. For the cases where either a nuclear weapon burns or explodes prior to nuclear fission, or at locations close to a nuclear reactor accident containing fission products, a major concern is the inhalation of aerosolized plutonium (Pu) particles producing alpha-radiation. We

Jospeh H. Shinn

1998-01-01

449

The Human Plutonium Injection Experiments William Moss and Roger Eckhardt  

E-print Network

atomic bombs. The idea was to remove a worker from the job if and when it was determined that the he had Need for Plutonium In planning the development of the atomic bomb, scientists considered using two unknown and uncharacterized materials to build the first atomic weapons. The Manhattan Project and Its

Massey, Thomas N.

450

Factors affecting plant absorption, transport and fate of plutonium  

Microsoft Academic Search

This study determined the extent to which several agricultural plants control plutonium (Pu) uptake and provides a general understanding of the fate and behavior of Pu in plants after absorption. Investigations were directed toward variables affecting the accumulation of Pu by plants from soils, transport of Pu within the plant, factors affecting transport with plant age, effects of different plant

T. R. Garland; D. A. Cataldo; K. M. McFadden; R. E. Wildung

1984-01-01

451

A strategy for weapons-grade plutonium disposition  

Microsoft Academic Search

A political as well as technical analysis was performed to determine the feasibility of glassification (vitrification) for weapons grade plutonium (WGPu) disposition. The political analysis provided the criteria necessary to compare alternative storage forms. The technical areas of weapon useability and environmental safety were then computationally and experimentally explored and a vitrification implementation strategy postulated. The Monte Carlo Neutron Photon

Sylvester; K. W. B

1994-01-01

452

Determination of plutonium traces in some German river sediments  

Microsoft Academic Search

The tiny plutonium contamination of river sediments near a nuclear research center was measured with conventional radiochemical techniques. One could observe that up to some 10% of the emitted ar-activities were due to transuranium isotopes, the rest was due to uranium and thorium, resp. their decay products. The radioecological relevance of this observation is discussed.

H. Barth; M. Ganz; S. Heise; D. Molzahn; R. Brandt; H. Klös

1993-01-01

453

Ternary Phase Diagrams that Relate to the Plutonium Immobilization Ceramic.  

National Technical Information Service (NTIS)

The plutonium immobilization ceramic consists primarily of a pyrochlore titanate phase of the approximate composition Ca0.97Hf0.17Pu0.22U0.39Gd0.24 Ti2O7. In this study, a series of ternary phase diagrams was constructed to evaluate the relationship of va...

B. B. Ebbinghaus, O. H. Krikorian, E. R. Vance

2001-01-01

454

Cerium as a surrogate in the plutonium immobilization waste form  

Microsoft Academic Search

In the aftermath of the Cold War, approximately 50 tonnes (MT) of weapons useable plutonium (Pu) has been identified as excess. The U.S. Department of Energy (DOE) has decided that at least a portion of this material will be immobilized in a titanate-based ceramic for final disposal in a geologic repository. The baseline formulation was designed to produce a ceramic

James Christopher Marra

2002-01-01

455

PROCESS OF REDUCING PLUTONIUM TO TETRAVALENT TRIVALENT STATE  

Microsoft Academic Search

The reduction of hexavalent and tetravalert plutonium ions to the ; trivalent state in strong nitric acid can be accomplished with hydrogen peroxide. ; The trivalent state may be stabilized as a precipitate by including oxalate or ; fluoride ions in the solution. The acid should be strong to encourage the ; reduction from the plutonyl to the trivalent state

Mastick

1960-01-01

456

Plutonium distribution: Summary of public and governmental support issues  

SciTech Connect

Obtaining strong public and governmental support for the plutonium disposition program and for the projects comprising the selected disposition options will be essential to the success of the program in meeting non-proliferation goals established as national policy. This paper summarizes issues related to public and governmental support for plutonium disposition. Recommendations are offered which rest on two fundamental assumptions: (1) public and political support derive from public trust and confidence, and (2) despite widespread support for U.S. non-proliferation goals, establishing and operating facilities to carry out the program will entail controversy. Documentation for the Administration`s policy on non-proliferation as it relates to plutonium disposition is cited and summarized as background for ongoing planning efforts by the Department of Energy (DOE). Consensus is a reasonable goal for efforts to secure public and governmental support for the plutonium disposition program and its elements; unanimity is very unlikely. The program will be aided by the popular recognition of the importance of the nation`s non-proliferation goals, the potential for an energy dividend if an energy production option is selected ({open_quotes}Swords to Plowshares{close_quotes} metaphor), the possibility of influencing disposition decisions in other countries, and the clear need to do something with the excess material ({open_quotes}the no action alternative{close_quotes} will not suffice).

Pasternak, A.

1995-03-31

457

N-Pu-U (Nitrogen-Plutonium-Uranium)  

NASA Astrophysics Data System (ADS)

This document is part of Subvolume C4 'Non-Ferrous Metal Systems. Part 4: Selected Nuclear Materials and Engineering Systems' of Volume 11 'Ternary Alloy Systems - Phase Diagrams, Crystallographic and Thermodynamic Data critically evaluated by MSIT®' of Landolt-Börnstein - Group IV 'Physical Chemistry'. It provides data of the ternary system Nitrogen-Plutonium-Uranium.

Materials Science International Team MSIT

458

O-Pu-U (Oxygen-Plutonium-Uranium)  

NASA Astrophysics Data System (ADS)

This document is part of Subvolume C4 'Non-Ferrous Metal Systems. Part 4: Selected Nuclear Materials and Engineering Systems' of Volume 11 'Ternary Alloy Systems - Phase Diagrams, Crystallographic and Thermodynamic Data critically evaluated by MSIT®' of Landolt-Börnstein - Group IV 'Physical Chemistry'. It provides data of the ternary system Oxygen-Plutonium-Uranium.

Materials Science International Team MSIT

459

Model for the age-dependent skeletal retention of plutonium  

SciTech Connect

A mathematical model of the metabolic and physiologic processes involved in the retention and translocation of plutonium in the body. The implications of the model concerning the dose as a function of age to radiosensitive tissues of the skeleton are examined. 16 references, 1 figure. (ACR)

Leggett, R.W.; Eckerman, K.F.

1984-01-01

460

Electrorefining of uranium and plutonium — A literature review  

NASA Astrophysics Data System (ADS)

This report is a comprehensive review of the literature on uranium and plutonium electrorefining in molten salts. It covers work published from 1943 to November 1991. Electrodeposition and electrodissolution at solid and liquid metal electrodes are discussed as well as mass transfer in liquid metal and molten salt phases.

Willit, J. L.; Miller, W. E.; Battles, J. E.

1992-11-01

461

Plutonium, americium, and neptunium speciation in selected groundwaters  

SciTech Connect

As part of a continuing study, plutonium, americium, and neptunium speciation was determined at 25 and 90/sup 0/C in four groundwaters from diverse sources: the Sparta aquifer in Louisiana, near the Vacherie salt dome; Mansfield No. 2 well in the Palo Duro Basin, Texas; the Stripa mine in Sweden; and the Waste Isolation Pilot Plant in New Mexico. Plutonium generally was soluble in Sparta and Stripa waters, regardless of temperature or initial oxidation state. Solubility in Mansfield water was high, except in 90/sup 0/C experiments using low-oxidation-state plutonium. The WIPP water had the least ability to maintain plutonium in solution; solubility after 30 days exceeded 50% only in experiments at 25/sup 0/C using Pu(V) and Pu(VI) (Neptunium generally was soluble in all waters and was present exclusively as Np(V) and Np(VI), regardless of initial oxidation state.) The solubility of americium was consistently high in Sparta groundwater at both temperatures and in Mansfield and WIPP waters at 25/sup 0/C, but was < 50% after 30 days in Stripa water at both temperatures and in Mansfield and WIPP waters at 90/sup 0/C. (The results indicated that plutonium and neptunium solubilities were determined by the oxidation-reduction properties of the waters, i.e., their abilities to convert these elements to soluble oxidation states. This was not the case for americium, however; Am(IV) was not detected, and the solubility of this element was determined entirely by the chemical properties of Am(III).

Cleveland, J.M.; Nash, K.L.; Rees, T.F.

1985-06-01

462

Carbon Dioxide for pH Control  

SciTech Connect

Cardox, the major supplier of carbon dioxide, has developed a diffuser to introduce carbon dioxide into a water volume as small bubbles to minimize reagent loss to the atmosphere. This unit is integral to several configurations suggested for treatment to control alkalinity in water streams.

Wagonner, R.C.

2001-08-16

463

A new look at atmospheric carbon dioxide  

Microsoft Academic Search

Carbon dioxide is increasing in the atmosphere and is of considerable concern in global climate change because of its greenhouse gas warming potential. The rate of increase has accelerated since measurements began at Mauna Loa Observatory in 1958 where carbon dioxide increased from less than 1 part per million per year (ppmyr?1) prior to 1970 to more than 2ppmyr?1 in

David J. Hofmann; James H. Butler; Pieter P. Tans

2009-01-01

464

The Impact of Carbon Dioxide on Climate.  

ERIC Educational Resources Information Center

Examines the relationship between climatic change and carbon dioxide from the historical perspective; details the contributions of carbon-based fuels to increasing carbon dioxide concentrations; and using global circulation models, discusses the future impact of the heavy reliance of our society on carbon-based fuels on climatic change. (BT)

MacDonald, Gordon J.

1979-01-01

465

Residential carbon dioxide emissions in Canada  

Microsoft Academic Search

The effect of improving house envelope, heating system and appliance efficiencies, and fuel substitution on the atmospheric emissions of carbon dioxide in the Canadian residential sector is studied based on simulation studies. The findings clearly indicate that improving appliance efficiency reduces the overall end-use energy consumption in the residential sector as well as the associated carbon dioxide emissions. However, the

V. Ismet Ugursal; Alan S. Fung

1998-01-01

466

Interglacials, Milankovitch Cycles, and Carbon Dioxide  

E-print Network

The existing understanding of interglacial periods is that they are initiated by Milankovitch cycles enhanced by rising atmospheric carbon dioxide concentrations. During interglacials, global temperature is also believed to be primarily controlled by carbon dioxide concentrations, modulated by internal processes such as the Pacific Decadal Oscillation and the North Atlantic Oscillation. Recent work challenges the fundamental basis of these conceptions.

Marsh, Gerald E

2010-01-01

467

Carbon dioxide sequestration by mineral carbonation  

Microsoft Academic Search

The increasing atmospheric carbon dioxide (CO2) concentration, mainly caused by fossil fuel combustion, has lead to concerns about global warming. A possible technology that can contribute to the reduction of carbon dioxide emissions is CO2 sequestration by mineral carbonation. The basic concept behind mineral CO2 sequestration is the mimicking of natural weathering processes in which calcium or magnesium containing minerals

W. J. J. Huijgen; R. N. J. Comans

2007-01-01

468

CHLORINE DIOXIDE FOR DRINKING WATER RESEARCH DIVISION  

EPA Science Inventory

In order to comply with the trihalomethane regulation, many drinking water utilities have had to alter their treatment methods. ne option available to these utilities is to use a disinfectant other than chlorine such as chlorine dioxide. ith chlorine dioxide disinfection, trihalo...

469

Optimize carbon dioxide sequestration, enhance oil recovery  

E-print Network

- 1 - Optimize carbon dioxide sequestration, enhance oil recovery January 8, 2014 Los Alamos simulation to optimize carbon dioxide (CO2) sequestration and enhance oil recovery (CO2-EOR) based on known production. Due to carbon capture and storage technology advances, prolonged high oil prices

470

Interglacials, Milankovitch Cycles, and Carbon Dioxide  

E-print Network

The existing understanding of interglacial periods is that they are initiated by Milankovitch cycles enhanced by rising atmospheric carbon dioxide concentrations. During interglacials, global temperature is also believed to be primarily controlled by carbon dioxide concentrations, modulated by internal processes such as the Pacific Decadal Oscillation and the North Atlantic Oscillation. Recent work challenges the fundamental basis of these conceptions.

Gerald E. Marsh

2010-02-02

471

MODELING OF DIFFUSION OF PLUTONIUM IN OTHER METALS AND OF GASEOUS SPECIES IN PLUTONIUM-BASED SYSTEMS  

EPA Science Inventory

The research is aimed at developing and utilizing computational-modeling-based methodology to treat two major problems. The first of these is to be able to predict the diffusion of plutonium from the surface into the interior of another metal such as uranium or stainless steel (f...

472

Analysis of naturally produced technetium and plutonium in geologic materials.  

PubMed

In uncontaminated natural materials, plutonium and technetium exist exclusively as products (daughters) of nuclear reactions in which uranium is the principal reactant (parent). Under conditions of chemical stability over geologic periods of time, the relative abundances of daughter and parent elements are fixed by the rates of nuclear reactions and the decay of the daughter radionuclide. The state of this nuclear secular equilibrium condition is the primary basis of the geochemical study of these elements in nature. Thus, it is critical that nuclear parent and daughter abundances are measured in the same sample. We have developed a quantitative procedure for measuring subpicogram quantities of plutonium and technetium in gram quantities of geologic matrices such as uranium ores. The procedure takes advantage of the aggressive properties of sodium peroxide/hydroxide fusion to ensure complete dissolution and homogenization of complex materials, the precision provided by isotope dilution techniques, and the extreme sensitivity offered by thermal ionization mass spectrometry. Using this technique, a quantitative aliquot can be removed for uranium analysis by isotope dilution thermal ionization mass spectrometry or ? spectrometry. Although the application of the procedure is unique, the analytical concepts may find more general application in studies of environmental contamination by nuclear materials. To assess the precision and accuracy of the analytical results, blanks and standards were analyzed routinely for a 1-year period to ensure quality control of our sample analyses. The average technetium blank is 5 ± 4 fg (n = 8), and that for plutonium is 0.17 ± 0.15 pg (n = 7). Thus, the detection limit for technetium (defined as 3 times the standard deviation of the average blank) is 11 fg, and that for plutonium is 0.44 pg. To assess the procedural precision, Canadian Reference Material BL-5 was analyzed routinely with samples. The results of seven replicate analyses for technetium in this standard reference material yield a technetium concentration of 59.0 fg/g, with a remarkably small standard deviation of 0.6 fg, 1.0% of the average value. The results of six replicate analyses for the concentration of plutonium in BL-5 give 1.012 pg/g, with an equally small standard deviation of 0.016, 1.6% of the average value. No direct measure of accuracy can be done on the technetium or plutonium analyses, because no standard reference material exists for these elements. To help constrain the accuracy of our measurements, equilibrium technetium/uranium and plutonium/uranium abundances were calculated using the nuclear reaction code MCNP. For technetium, such calculations are relatively insensitive to variations in model parameters, and measurements fall within a 21% high/low bias. For plutonium, the calculations are very sensitive to model parameters and hence inherently less precise. Indirectly, spike and isotope mix calibrations made from weighted quantities of certified isotopes (both technetium and plutonium) can be used to determine the bias of the measurement system for these elements. These calibrations show that the measurement system is biased by no more than ±1.5%. PMID:21639292

Dixon, P; Curtis, D B; Musgrave, J; Roensch, F; Roach, J; Rokop, D

1997-05-01

473

EXAFS and XANES analysis of plutonium and cerium edges from titanate ceramics for fissile materials disposal.  

SciTech Connect

We report x-ray absorption near edge structure (XANES) and extended x-ray absorption fine structure (EXAFS) spectra from the plutonium L{sub III} edge and XANES from the cerium L{sub II} edge in prototype titanate ceramic hosts. The titanate ceramics studied are based upon the hafnium-pyrochlore and zirconolite mineral structures and will serve as an immobilization host for surplus fissile materials, containing as much as 10 weight % fissile plutonium and 20 weight % (natural or depleted) uranium. Three ceramic formulations were studied: one employed cerium as a ''surrogate'' element, replacing both plutonium and uranium in the ceramic matrix, another formulation contained plutonium in a ''baseline'' ceramic formulation, and a third contained plutonium in a formulation representing a high-impurity plutonium stream. The cerium XANES from the surrogate ceramic clearly indicates a mixed III-IV oxidation state for the cerium. In contrast, XANES analysis of the two plutonium-bearing ceramics shows that the plutonium is present almost entirely as Pu(IV) and occupies the calcium site in the zirconolite and pyrochlore phases. The plutonium EXAFS real-space structure shows a strong second-shell peak, clearly distinct from that of PuO{sub 2}, with remarkably little difference in the plutonium crystal chemistry indicated between the baseline and high-impurity formulations.

Fortner, J. A.; Kropf, A. J.; Bakel, A. J.; Hash, M. C.; Aase, S. B.; Buck, E. C.; Chamerlain, D. B.

1999-11-16

474

Proceedings of the 6th Annual Meeting for Excess Weapons Plutonium Disposition: Plutonium Packaging, Storage and Transportation and WasteTreatment, Storage and Disposal Activities  

Microsoft Academic Search

The sixth annual Excess Weapons Plutonium Disposition meeting organized by Lawrence Livermore National Laboratory (LLNL) was held November 15-17, 2004, at the State Education Center (SEC), 4 Aerodromnya Drive, St. Petersburg, Russia. The meeting discussed Excess Weapons Plutonium Disposition topics for which LLNL has the US Technical Lead Organization responsibilities. The technical areas discussed included Radioactive Waste Treatment, Storage, and

Jardine

2005-01-01

475

Microfluidic studies of carbon dioxide.  

PubMed

Carbon dioxide (CO2) sequestration, storage and recycling will greatly benefit from comprehensive studies of physical and chemical gas-liquid processes involving CO2. Over the past five years, microfluidics emerged as a valuable tool in CO2-related research, due to superior mass and heat transfer, reduced axial dispersion, well-defined gas-liquid interfacial areas and the ability to vary reagent concentrations in a high-throughput manner. This Minireview highlights recent progress in microfluidic studies of CO2-related processes, including dissolution of CO2 in physical solvents, CO2 reactions, the utilization of CO2 in materials science, and the use of supercritical CO2 as a "green" solvent. PMID:24961230

Abolhasani, Milad; Günther, Axel; Kumacheva, Eugenia

2014-07-28

476

Introducing equipment and plutonium glove box modifications for monitoring gas generation over plutonium oxide materials.  

SciTech Connect

DOE is embarking on a program to store large quantities of Pu-bearing materials for up to fifty years. Materials for long-term storage are metals and oxides that are stabilized and packaged according to the DOE storage standard. Experience with PuO, materials has shown that gases generated by catalytic and/or radiolytic processes may accumulate. Of concern are the generation of H, gas from adsorbed water and the generation of HCI or CI, gases from the radiolysis of chloride-containing salts. We have designed instrumented storage containers that mimic the inner storage can specified in the standard. The containers and surveillance equipment are interfaced with a plutonium glovebox and are designed to allow the gas composition and pressure to be monitored over time. The surveillance activities and glovebox interfaces include Raman fiber optic probes, a gas analysis sampling port, corrosion monitors, and pressure and temperature feedthrus. Data collection for these containers is automated in order to reduce worker exposure. The equipment design and glovebox modifications are presented.

Padilla, D. D. (Dennis D.); Berg, J. M. (John M.); Carrillo, A. G. (Alejandro G.); Montoya, A. R. (Adam R.); Morris, J. S. (John S.); Veirs, D. K. (Douglas Kirk); Martinez, M. A. (Max A.); Worl, L. A. (Laura A.); Harradine, D. M. (David M.); Hill, D. D. (Dallas D.)

2002-01-01

477

Plutonium immobilization plant using ceramic in existing facilities at the Savannah River site  

SciTech Connect

The Plutonium Immobilization Plant (PIP) accepts plutonium (Pu) from pit conversion and from non-pit sources, and through a ceramic immobilization process converts the plutonium into an immobilized form that can be disposed of in a high level waste (HLW) repository. This immobilization process is shown conceptually in Figure 1-1. The objective is to make an immobilized form, suitable for geologic disposal, in which the plutonium is as inherently unattractive and inaccessible as the plutonium in spent fuel from commercial reactors. The ceramic immobilization alternative presented in this report consists of first converting the surplus material to an oxide, followed by incorporating the plutonium oxide into a titanate-based ceramic material that is placed in metal cans.

DiSabatino, A., LLNL

1998-06-01

478

Preparation of acid standards for and determination of free acid in concentrated plutonium-uranium solutions  

SciTech Connect

Standard nitric acid solutions containing up to 400 g/L plutonium and/or uranium were prepared and these provide a way of rigorously testing methods for the determination of free acid in concentrated plutonium solutions. These standard solutions were prepared from uranyl nitrate hexahydrate and crystalline plutonium(IV) nitrate which was in turn obtained by vacuum evaporation of nitric acid solutions of Pu(IV). Three methods of free acid determination in plutonium solutions were tested, and the widely accepted iodate precipitation methods was shown to give markedly erroneous results at high plutonium concentrations. An improved oxalate complexing procedure was developed which gives accurate results (bias less than the standard deviation of 0.02 M) up to at least 400 g/L plutonium. 27 references, 2 figures, 2 tables.

Ryan, J.L.; Bryan, G.H.; Burt, M.C.; Costanzo, D.A.

1985-06-01

479

Controllability of plutonium concentration for FBR fuel at a solvent extraction process in the PUREX process  

SciTech Connect

Typical Purex solvent extraction systems for the reprocessing of spent nuclear fuel have a feed material containing dilute, 1% in weight, plutonium, along with uranium and fission products. Current reprocessing proposals call for no separation of the pure plutonium. The work described in this paper studied, by computer simulation, the fundamental feasibility of preparing a 20% concentrated plutonium product solution from the 1% feed by adjusting only the feed rates and acid concentrations of the incoming streams and without the addition of redox reagents for the plutonium. A set of process design flowsheets has been developed to realize a concentrated plutonium solution of a 20% stream from the dilute plutonium feed without using redox reagents. (authors)

Enokida, Youichi; Kitano, Motoki; Sawada, Kayo [Nagoya University, 1 Furo-cho, Chikusa-ku, Nagoya-shi, Aichi-ken, 4630052 (Japan)

2013-07-01

480

Liquid-metal embrittlement of refractory metals by molten plutonium  

SciTech Connect

Embrittlement by molten plutonium of the refractory metals and alloys W-25 wt % Re, tantalum, molybdenum, and Ta-10 wt % W was studied. At 900/sup 0/C and a strain rate of 10/sup -4/ s/sup -1/, the materials tested may be ranked in order of decreasing susceptibility to liquid-plutonium embrittlement as follows: molybdenum, W-25 wt % Re, Ta-10 wt % W, and tantalum. These materials exhibited a wide range in susceptibility. Embrittlement was found to exhibit a high degree of temperature and strain-rate dependence, and we present arguments that strongly support a stress-assisted, intergranular, liquid-metal corrosion mechanism. We also believe microstructure plays a key role in the extent of embrittlement. In the case of W-25 wt % Re, we have determined that a dealloying corrosion takes place in which rhenium is selectively withdrawn from the alloy.

Lesuer, D.R.; Bergin, J.B.; McInturff, S.A.; Kuhn, B.A.

1980-07-01

481

STAINLESS STEEL INTERACTIONS WITH SALT CONTAINING PLUTONIUM OXIDES  

SciTech Connect

Salt containing plutonium oxide materials are treated, packaged and stored within nested, stainless steel containers based on requirements established in the DOE 3013 Standard. The moisture limit for the stored materials is less than 0.5 weight %. Surveillance activities which are conducted to assess the condition of the containers and assure continuing 3013 container integrity include the destructive examination of a select number of containers to determine whether corrosion attack has occurred as a result of stainless steel interactions with salt containing plutonium oxides. To date, some corrosion has been observed on the innermost containers, however, no corrosion has been noted on the outer containers and the integrity of the 3013 container systems is not expected to be compromised over a 50 year storage lifetime.

Nelson, Z.; Chandler, G.; Dunn, K.; Stefek, T.; Summer, M.

2010-02-01

482

Status and trends in plutonium recycling in nuclear power reactors  

NASA Astrophysics Data System (ADS)

Already during the well-known IAEA International Fuel Cycle Evaluation Study of 1976-80,[1] the different aspects of plutonium utilization in the form of MOX fuel were discussed and followed up in the many international meetings during the last two decades. An International Symposium on MOX Fuel Cycle Technologies for Medium and Long Term Deployment, organized by the IAEA in co-operation with OECD/NEA and held in Vienna in May 1999, was a milestone which reviewed the past, present and future of Pu recycling in nuclear power reactors.[2] This paper presents major results of the Symposium in the context of present conditions of deregulated electricity market and in the future and its role in the reduction of stockpiles of separated civil and surplus ex-weapons plutonium.

Onoufriev, Vladimir

2000-07-01

483

Education, Convergence and Carbon Dioxide Growth per Capita  

E-print Network

65 Education, Convergence and Carbon Dioxide Growth per Capita Kinda Somlanare Romuald Abstract dioxide emissions around the world, and that education is not a factor in carbon dioxide emissions growth, there is no convergence, and that education is not a factor in carbon dioxide growth. In developed countries, we find

Paris-Sud XI, Université de

484

Carbon dioxide emission scenarios: limitations of the fossil fuel resource  

Microsoft Academic Search

Contemporary increases in atmospheric carbon dioxide concentration are in large part the result of anthropogenic carbon dioxide emissions from fossil fuel combustion. Scenario analysis is commonly used to generate projections of future carbon dioxide emissions, the resulting atmospheric concentrations and climate impact. In most scenario modelling published to date, carbon dioxide emission scenarios are based on demand-side (socioeconomic and technology)

Christopher Vernon; Erica Thompson; Sarah Cornell

2011-01-01

485

Methane-assisted combustion synthesis of nanocomposite tin dioxide materials  

E-print Network

Methane-assisted combustion synthesis of nanocomposite tin dioxide materials S.D. Bakrania *, C., Ann Arbor, MI 48109-2125, USA Abstract Combustion synthesis of tin dioxide (SnO2) was studied using: Combustion synthesis; Nanoparticles; Tin dioxide; Metals 1. Introduction Tin dioxide (SnO2) is the most

Wooldridge, Margaret S.

486

Characterization and storage of the Rocky Flats plutonium oxide legacy  

Microsoft Academic Search

Prior to 1989, plutonium oxide storage at the U.S. Department of Energy (DOE) Rocky Flats Environmental Technology Site (RFETS) could generally be considered as short term. Packaging configurations for short-term storage consisted of slip-lid cans and sealed produce cans. Prior to packaging, most of the oxide had been stabilized by heating to â¼500°C. When storage times were relatively short, few

Stakebake

1997-01-01

487

NEUTRON SPECTRUM OF A PLUTONIUM-BERYLLIUM SOURCE  

Microsoft Academic Search

The neutron spectrum of a plutonium-beryllium source was obtained with ; the use of nuclear emulsions. Intensity maxima exist at less than 1.0 and at ; 3.2, 4.7, 7.7, and 9.7 Mev. Maxima at 4.7, 7.7, and 9.7 Mev are well accounted ; for in a calculated spectrum. Those at less than 1.0 and at 3.2 Mev are ; partially

M Edward Anderson; W. H. Jr. Bond

1963-01-01

488

PLUTONIUM-BERYLLIUM NEUTRON SOURCES THEIR FABRICATION AND THEIR YIELD  

Microsoft Academic Search

An investigntion of the plutonium-beryllium phase diagram demonstrates ;\\u000a the suitability of these alloys and most particularly the intermetallic compound ;\\u000a PuBeââ for stable neutron sources. These sources are superior to polonium-;\\u000a beryllium sources in respect to sthbility of neutron yield as a iunction of time ;\\u000a and the prediotability of neutroc yield as a function of mass. The gamma-ray

R. E. Tate; A. S. Coffinberry

1958-01-01

489

REACTIONS OF SODIUM PEROXIDE WITH COMPONENTS OF LEGACY PLUTONIUM MATERIALS  

Microsoft Academic Search

Plutonium oxide (PuO) calcined at >900 C resists dissolution in nitric acid (HNO)-potassium fluoride (KF) solutions, a common method for their dissolution. The Savannah River National Laboratory (SRNL) has developed an alternate method for large samples of PuO-bearing materials using sodium peroxide (NaO) fusion as a pretreatment. The products of the reaction between NaO and PuO have been reported in

R. Pierce; D. Missimer; M. Crowder

2011-01-01

490

Luminescent determination of neptunium and plutonium in the environment  

Microsoft Academic Search

The possibilities of membrane preconcentration of neptunium and plutonium from acidic soil leach have been studied. The elaborated technique involves two steps: liquid extraction of Pu(IV) and Np(IV) by HDEHP from the soil leach and accumulation of these elements by solid supported aqueous membrane with K10P2W17O61 in inner solution. It has been shown that actinide's content in the membrane can

A. P. Novikov; M. N. Mikheeva; O. I. Gracheva; B. F. Myasoedov

1997-01-01

491

PLUTONIUM238 RECOVERY FROM IRRADIATED NEPTUNIUM TARGETS USING SOLVENT EXTRACTION  

Microsoft Academic Search

The United States Department of Energy proposes to re-establish a domestic capability for producing plutonium-238 (238Pu) to fuel radioisotope power systems primarily in support of future space missions. A conceptual design report is currently being prepared for a new 238Pu, and neptunium-237 (237Np) target fabrication and processing facility tentatively to be built at the Idaho National Laboratory (INL) in the

Scott Herbst; Terry Todd; Jack Law; Bruce Mincher; Steve Frank; John Swanson

2006-01-01

492

Natural radionuclide and plutonium content in Black Sea bottom sediments  

SciTech Connect

The content of uranium, thorium, radium, lead, polonium, and plutonium in bottom sediments and algae from two locations at the Bulgarian Black Sea coast have been determined. Some parent:progeny ratios for evaluation of the geochemical behavior of the nuclides have been estimated as well. The extractable and total uranium and thorium are determined by two separate radiochemical procedures to differentiate the more soluble chemical forms of the elements and to estimate the potential hazard for the biosphere and for humans. No distinct seasonal variation as well as no significant change in total and extractable uranium (also for {sup 226}Ra) content is observed. The same is valid for extractable thorium while the total thorium content in the first two seasons is slightly higher. Our data show that {sup 210}Po content is accumulated more in the sediments than {sup 210}Pb, and the evaluated disequilibria suggest that the two radionuclides belong to more recent sediment layers deposited in the slime samples compared to the silt ones for the different seasons. The obtained values for plutonium are in the lower limits of the data cited in literature, which is quite clear as there are no plutonium discharge facilities at the Bulgarian Black Sea coast. The obtained values for the activity ratio {sup 238}Pu: {sup 239+240}Pu are higher for Bjala sediments compared to those of Kaliakra. The ratio values are out of the variation range for the global contamination with weapon tests fallout plutonium which is probably due to Chernobyl accident contribution. The dependence of natural radionuclide content on the sediment type as well as the variation of nuclide accumulation for two types of algae in two sampling locations for five consecutive seasons is evaluated. No serious contamination with natural radionuclides in the algae is observed. 38 refs., 6 figs., 7 tabs.

Strezov, A.; Stoilova, T. [Inst. for Nuclear Research and Nuclear Energy, Sofia (Bulgaria); Yordanova, I. [Inst. for Soil Science and Agroecology, Sofia (Bulgaria)] [and others

1996-01-01

493

System design document for the plutonium stabilization and packaging system  

SciTech Connect

The objective of this system is to stabilize and package plutonium metals and oxides of greater than 50% wt, as well as other selected isotopes, in accordance with the requirements for DOE standards for safe storage of these materials for 50 years. This document describes the highest level design information and user characteristics from an operational perspective. It provides guidance for developing procurement and installation specifications, interface requirements, and test plans.

NONE

1996-05-08

494

Ingestion Pathway Transfer Factors for Plutonium and Americium  

SciTech Connect

Overall transfer factors for major ingestion pathways are derived for plutonium and americium. These transfer factors relate the radionuclide concentration in a given foodstuff to deposition on the soil. Equations describing basic relationships consistent with Regulatory Guide 1.109 are followed. Updated values and coefficients from IAEA Technical Reports Series No. 364 are used when a available. Preference is given to using factors specific to the Savannah River Site.

Blanchard, A.

1999-07-28

495

Plutonium238 in sediment cores from the Mound Laboratory area  

Microsoft Academic Search

Plutonium-238 concentrations in 8 sediment cores from water bodies near Mound Laboratory are reported. All have been measurably contaminated and for the most part show concentrations with depth in the sediment suggesting that chemical and\\/or biological processes may be quite active, and that run-off from nearby contaminated soil is probably continuing. The integrated Pu-238 deposits indicate that these samples essentially

Volchok

1976-01-01

496

US weapons-useable plutonium disposition policy: implementation of the MOX fuel option  

E-print Network

as the Department of Nuclear Engineering for contributions made to my graduate education. The Amarillo National Resource Center for Plutonium has also made significant contributions in support of this study and my graduate education. This study and my gmduate... ABSTRACT ACKNOWLEDGMENTS. TABLE OF CONTENTS CHAPTER I INTRODUCTION. . II U. S. PLUTONIUM PRODUCTION AND USE . . . . . U. S. Plutonium Policy. III NONPROLIFERATION POLICY . 13 International Nuclear Nonproliferation Regime. . . . . U. S...

Gonzalez, Vanessa L

2012-06-07

497

Anticipated Radiological Dose to Worker for Plutonium Stabilization and Handling at PFP Project W-460  

SciTech Connect

This report provides estimates of the expected whole body and extremity radiological dose, expressed as dose equivalent (DE), to workers conducting planned plutonium (Pu) stabilization processes at the Hanford Site Plutonium Finishing Plant (PFP). The report is based on a time and motion dose study commissioned for Project W-460, Plutonium Stabilization and Handling, to provide personnel exposure estimates for construction work in the PFP storage vault area plus operation of stabilization and packaging equipment at PFP.

WEISS, E.V.

2000-03-06

498

Dose Rates from Plutonium Metal and Beryllium Metal in a 9975 Shipping Container  

SciTech Connect

A parametric study was performed of the radiation dose rates that might be produced if plutonium metal and beryllium metal were shipped in the 9975 shipping package. These materials consist of heterogeneous combinations plutonium metal and beryllium. The plutonium metal content varies up to 4.4 kilograms while the beryllium metal varies up to 4 kilograms. This paper presents the results of that study.

Nathan, S.J.

2002-02-04

499

Selection of Russian Plutonium Beryllium Sources for Inclusion in the Nuclear Mateirals Information Program Archive  

Microsoft Academic Search

Throughout the 1960s and 1970s, the former Soviet Union produced and exported Plutonium-Beryllium (PuBe) neutron sources to various Eastern European countries. The Russian sources consist of an intermetallic compound of plutonium and beryllium encapsulated in an inner welded, sealed capsule and consisting of a body and one or more covers. The amount of plutonium in the sources ranges from 0.002

Joshua E Narlesky; Dennis D Padilla; Joe Watts

2009-01-01

</